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<li><a class="reference internal" href="#">Python Initialization Configuration</a><ul>
<li><a class="reference internal" href="#example">Example</a></li>
<li><a class="reference internal" href="#pywidestringlist">PyWideStringList</a></li>
<li><a class="reference internal" href="#pystatus">PyStatus</a></li>
<li><a class="reference internal" href="#pypreconfig">PyPreConfig</a></li>
<li><a class="reference internal" href="#preinitialize-python-with-pypreconfig">Preinitialize Python with PyPreConfig</a></li>
<li><a class="reference internal" href="#pyconfig">PyConfig</a></li>
<li><a class="reference internal" href="#initialization-with-pyconfig">Initialization with PyConfig</a></li>
<li><a class="reference internal" href="#isolated-configuration">Isolated Configuration</a></li>
<li><a class="reference internal" href="#python-configuration">Python Configuration</a></li>
<li><a class="reference internal" href="#python-path-configuration">Python Path Configuration</a></li>
<li><a class="reference internal" href="#py-runmain">Py_RunMain()</a></li>
<li><a class="reference internal" href="#py-getargcargv">Py_GetArgcArgv()</a></li>
<li><a class="reference internal" href="#multi-phase-initialization-private-provisional-api">Multi-Phase Initialization Private Provisional API</a></li>
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 <section id="python-initialization-configuration">
<h1>Python Initialization Configuration<a class="headerlink" href="#python-initialization-configuration" title="Permalink to this headline">¶</a></h1>
<div class="versionadded">
New in version 3.8.
</div>
Python can be initialized with <a class="reference internal" href="#c.Py_InitializeFromConfig" title="Py_InitializeFromConfig"><code class="xref c c-func docutils literal notranslate">Py_InitializeFromConfig()</code></a> and the
<a class="reference internal" href="#c.PyConfig" title="PyConfig"><code class="xref c c-type docutils literal notranslate">PyConfig</code></a> structure. It can be preinitialized with
<a class="reference internal" href="#c.Py_PreInitialize" title="Py_PreInitialize"><code class="xref c c-func docutils literal notranslate">Py_PreInitialize()</code></a> and the <a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig"><code class="xref c c-type docutils literal notranslate">PyPreConfig</code></a> structure.
There are two kinds of configuration:
<ul class="simple">
<li>The <a class="reference internal" href="#init-python-config">Python Configuration</a> can be used to build a
customized Python which behaves as the regular Python. For example,
environment variables and command line arguments are used to configure
Python.</li>
<li>The <a class="reference internal" href="#init-isolated-conf">Isolated Configuration</a> can be used to embed
Python into an application. It isolates Python from the system. For example,
environment variables are ignored, the LC_CTYPE locale is left unchanged and
no signal handler is registered.</li>
</ul>
The <a class="reference internal" href="#c.Py_RunMain" title="Py_RunMain"><code class="xref c c-func docutils literal notranslate">Py_RunMain()</code></a> function can be used to write a customized Python
program.
See also <a class="reference internal" href="init.html#initialization">Initialization, Finalization, and Threads</a>.
<div class="admonition seealso">
See also
<a class="pep reference external" href="https://www.python.org/dev/peps/pep-0587">PEP 587</a> “Python Initialization Configuration”.
</div>
<section id="example">
<h2>Example<a class="headerlink" href="#example" title="Permalink to this headline">¶</a></h2>
Example of customized Python always running in isolated mode:
<div class="highlight-c notranslate"><div class="highlight"><pre>int main(int argc, char **argv)
{
 PyStatus status;

PyConfig config;
 PyConfig_InitPythonConfig(&amp;config);
 config.isolated = 1;

/* Decode command line arguments.
 Implicitly preinitialize Python (in isolated mode). */
 status = PyConfig_SetBytesArgv(&amp;config, argc, argv);
 if (PyStatus_Exception(status)) {
 goto exception;
 }

status = Py_InitializeFromConfig(&amp;config);
 if (PyStatus_Exception(status)) {
 goto exception;
 }
 PyConfig_Clear(&amp;config);

return Py_RunMain();

exception:
 PyConfig_Clear(&amp;config);
 if (PyStatus_IsExit(status)) {
 return status.exitcode;
 }
 /* Display the error message and exit the process with
 non-zero exit code */
 Py_ExitStatusException(status);
}
</pre></div>
</div>
</section>
<section id="pywidestringlist">
<h2>PyWideStringList<a class="headerlink" href="#pywidestringlist" title="Permalink to this headline">¶</a></h2>
<dl class="c type">
<dt class="sig sig-object c" id="c.PyWideStringList">
type PyWideStringList<a class="headerlink" href="#c.PyWideStringList" title="Permalink to this definition">¶</a> </dt>
<dd>List of <code class="docutils literal notranslate">wchar_t*</code> strings.
If length is non-zero, items must be non-<code class="docutils literal notranslate">NULL</code> and all strings must be
non-<code class="docutils literal notranslate">NULL</code>.
Methods:
<dl class="c function">
<dt class="sig sig-object c" id="c.PyWideStringList.PyWideStringList_Append">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyWideStringList_Append(<a class="reference internal" href="#c.PyWideStringList" title="PyWideStringList">PyWideStringList</a> *list, const wchar_t *item)<a class="headerlink" href="#c.PyWideStringList.PyWideStringList_Append" title="Permalink to this definition">¶</a> </dt>
<dd>Append item to list.
Python must be preinitialized to call this function.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyWideStringList.PyWideStringList_Insert">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyWideStringList_Insert(<a class="reference internal" href="#c.PyWideStringList" title="PyWideStringList">PyWideStringList</a> *list, <a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t">Py_ssize_t</a> index, const wchar_t *item)<a class="headerlink" href="#c.PyWideStringList.PyWideStringList_Insert" title="Permalink to this definition">¶</a> </dt>
<dd>Insert item into list at index.
If index is greater than or equal to list length, append item to
list.
index must be greater than or equal to 0.
Python must be preinitialized to call this function.
</dd></dl>

Structure fields:
<dl class="c member">
<dt class="sig sig-object c" id="c.PyWideStringList.length">
<a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t">Py_ssize_t</a> length<a class="headerlink" href="#c.PyWideStringList.length" title="Permalink to this definition">¶</a> </dt>
<dd>List length.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyWideStringList.items">
wchar_t **items<a class="headerlink" href="#c.PyWideStringList.items" title="Permalink to this definition">¶</a> </dt>
<dd>List items.
</dd></dl>

</dd></dl>

</section>
<section id="pystatus">
<h2>PyStatus<a class="headerlink" href="#pystatus" title="Permalink to this headline">¶</a></h2>
<dl class="c type">
<dt class="sig sig-object c" id="c.PyStatus">
type PyStatus<a class="headerlink" href="#c.PyStatus" title="Permalink to this definition">¶</a> </dt>
<dd>Structure to store an initialization function status: success, error
or exit.
For an error, it can store the C function name which created the error.
Structure fields:
<dl class="c member">
<dt class="sig sig-object c" id="c.PyStatus.exitcode">
int exitcode<a class="headerlink" href="#c.PyStatus.exitcode" title="Permalink to this definition">¶</a> </dt>
<dd>Exit code. Argument passed to <code class="docutils literal notranslate">exit()</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyStatus.err_msg">
const char *err_msg<a class="headerlink" href="#c.PyStatus.err_msg" title="Permalink to this definition">¶</a> </dt>
<dd>Error message.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyStatus.func">
const char *func<a class="headerlink" href="#c.PyStatus.func" title="Permalink to this definition">¶</a> </dt>
<dd>Name of the function which created an error, can be <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

Functions to create a status:
<dl class="c function">
<dt class="sig sig-object c" id="c.PyStatus.PyStatus_Ok">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyStatus_Ok(void)<a class="headerlink" href="#c.PyStatus.PyStatus_Ok" title="Permalink to this definition">¶</a> </dt>
<dd>Success.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyStatus.PyStatus_Error">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyStatus_Error(const char *err_msg)<a class="headerlink" href="#c.PyStatus.PyStatus_Error" title="Permalink to this definition">¶</a> </dt>
<dd>Initialization error with a message.
err_msg must not be <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyStatus.PyStatus_NoMemory">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyStatus_NoMemory(void)<a class="headerlink" href="#c.PyStatus.PyStatus_NoMemory" title="Permalink to this definition">¶</a> </dt>
<dd>Memory allocation failure (out of memory).
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyStatus.PyStatus_Exit">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyStatus_Exit(int exitcode)<a class="headerlink" href="#c.PyStatus.PyStatus_Exit" title="Permalink to this definition">¶</a> </dt>
<dd>Exit Python with the specified exit code.
</dd></dl>

Functions to handle a status:
<dl class="c function">
<dt class="sig sig-object c" id="c.PyStatus.PyStatus_Exception">
int PyStatus_Exception(<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> status)<a class="headerlink" href="#c.PyStatus.PyStatus_Exception" title="Permalink to this definition">¶</a> </dt>
<dd>Is the status an error or an exit? If true, the exception must be
handled; by calling <a class="reference internal" href="#c.PyStatus.Py_ExitStatusException" title="Py_ExitStatusException"><code class="xref c c-func docutils literal notranslate">Py_ExitStatusException()</code></a> for example.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyStatus.PyStatus_IsError">
int PyStatus_IsError(<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> status)<a class="headerlink" href="#c.PyStatus.PyStatus_IsError" title="Permalink to this definition">¶</a> </dt>
<dd>Is the result an error?
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyStatus.PyStatus_IsExit">
int PyStatus_IsExit(<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> status)<a class="headerlink" href="#c.PyStatus.PyStatus_IsExit" title="Permalink to this definition">¶</a> </dt>
<dd>Is the result an exit?
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyStatus.Py_ExitStatusException">
void Py_ExitStatusException(<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> status)<a class="headerlink" href="#c.PyStatus.Py_ExitStatusException" title="Permalink to this definition">¶</a> </dt>
<dd>Call <code class="docutils literal notranslate">exit(exitcode)</code> if status is an exit. Print the error
message and exit with a non-zero exit code if status is an error. Must
only be called if <code class="docutils literal notranslate">PyStatus_Exception(status)</code> is non-zero.
</dd></dl>

</dd></dl>

<div class="admonition note">
Note
Internally, Python uses macros which set <code class="docutils literal notranslate">PyStatus.func</code>,
whereas functions to create a status set <code class="docutils literal notranslate">func</code> to <code class="docutils literal notranslate">NULL</code>.
</div>
Example:
<div class="highlight-c notranslate"><div class="highlight"><pre>PyStatus alloc(void **ptr, size_t size)
{
 *ptr = PyMem_RawMalloc(size);
 if (*ptr == NULL) {
 return PyStatus_NoMemory();
 }
 return PyStatus_Ok();
}

int main(int argc, char **argv)
{
 void *ptr;
 PyStatus status = alloc(&amp;ptr, 16);
 if (PyStatus_Exception(status)) {
 Py_ExitStatusException(status);
 }
 PyMem_Free(ptr);
 return 0;
}
</pre></div>
</div>
</section>
<section id="pypreconfig">
<h2>PyPreConfig<a class="headerlink" href="#pypreconfig" title="Permalink to this headline">¶</a></h2>
<dl class="c type">
<dt class="sig sig-object c" id="c.PyPreConfig">
type PyPreConfig<a class="headerlink" href="#c.PyPreConfig" title="Permalink to this definition">¶</a> </dt>
<dd>Structure used to preinitialize Python.
Function to initialize a preconfiguration:
<dl class="c function">
<dt class="sig sig-object c" id="c.PyPreConfig.PyPreConfig_InitPythonConfig">
void PyPreConfig_InitPythonConfig(<a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig">PyPreConfig</a> *preconfig)<a class="headerlink" href="#c.PyPreConfig.PyPreConfig_InitPythonConfig" title="Permalink to this definition">¶</a> </dt>
<dd>Initialize the preconfiguration with <a class="reference internal" href="#init-python-config">Python Configuration</a>.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyPreConfig.PyPreConfig_InitIsolatedConfig">
void PyPreConfig_InitIsolatedConfig(<a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig">PyPreConfig</a> *preconfig)<a class="headerlink" href="#c.PyPreConfig.PyPreConfig_InitIsolatedConfig" title="Permalink to this definition">¶</a> </dt>
<dd>Initialize the preconfiguration with <a class="reference internal" href="#init-isolated-conf">Isolated Configuration</a>.
</dd></dl>

Structure fields:
<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.allocator">
int allocator<a class="headerlink" href="#c.PyPreConfig.allocator" title="Permalink to this definition">¶</a> </dt>
<dd>Name of the Python memory allocators:
<ul class="simple">
<li><code class="docutils literal notranslate">PYMEM_ALLOCATOR_NOT_SET</code> (<code class="docutils literal notranslate">0</code>): don’t change memory allocators
(use defaults).</li>
<li><code class="docutils literal notranslate">PYMEM_ALLOCATOR_DEFAULT</code> (<code class="docutils literal notranslate">1</code>): <a class="reference internal" href="memory.html#default-memory-allocators">default memory allocators</a>.</li>
<li><code class="docutils literal notranslate">PYMEM_ALLOCATOR_DEBUG</code> (<code class="docutils literal notranslate">2</code>): <a class="reference internal" href="memory.html#default-memory-allocators">default memory allocators</a> with <a class="reference internal" href="memory.html#pymem-debug-hooks">debug hooks</a>.</li>
<li><code class="docutils literal notranslate">PYMEM_ALLOCATOR_MALLOC</code> (<code class="docutils literal notranslate">3</code>): use <code class="docutils literal notranslate">malloc()</code> of the C library.</li>
<li><code class="docutils literal notranslate">PYMEM_ALLOCATOR_MALLOC_DEBUG</code> (<code class="docutils literal notranslate">4</code>): force usage of
<code class="docutils literal notranslate">malloc()</code> with <a class="reference internal" href="memory.html#pymem-debug-hooks">debug hooks</a>.</li>
<li><code class="docutils literal notranslate">PYMEM_ALLOCATOR_PYMALLOC</code> (<code class="docutils literal notranslate">5</code>): <a class="reference internal" href="memory.html#pymalloc">Python pymalloc memory
allocator</a>.</li>
<li><code class="docutils literal notranslate">PYMEM_ALLOCATOR_PYMALLOC_DEBUG</code> (<code class="docutils literal notranslate">6</code>): <a class="reference internal" href="memory.html#pymalloc">Python pymalloc
memory allocator</a> with <a class="reference internal" href="memory.html#pymem-debug-hooks">debug hooks</a>.</li>
</ul>
<code class="docutils literal notranslate">PYMEM_ALLOCATOR_PYMALLOC</code> and <code class="docutils literal notranslate">PYMEM_ALLOCATOR_PYMALLOC_DEBUG</code> are
not supported if Python is <a class="reference internal" href="../using/configure.html#cmdoption-without-pymalloc"><code class="xref std std-option docutils literal notranslate">configured using --without-pymalloc</code></a>.
See <a class="reference internal" href="memory.html#memory">Memory Management</a>.
Default: <code class="docutils literal notranslate">PYMEM_ALLOCATOR_NOT_SET</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.configure_locale">
int configure_locale<a class="headerlink" href="#c.PyPreConfig.configure_locale" title="Permalink to this definition">¶</a> </dt>
<dd>Set the LC_CTYPE locale to the user preferred locale.
If equals to 0, set <a class="reference internal" href="#c.PyPreConfig.coerce_c_locale" title="PyPreConfig.coerce_c_locale"><code class="xref c c-member docutils literal notranslate">coerce_c_locale</code></a> and
<a class="reference internal" href="#c.PyPreConfig.coerce_c_locale_warn" title="PyPreConfig.coerce_c_locale_warn"><code class="xref c c-member docutils literal notranslate">coerce_c_locale_warn</code></a> members to 0.
See the <a class="reference internal" href="../glossary.html#term-locale-encoding">locale encoding</a>.
Default: <code class="docutils literal notranslate">1</code> in Python config, <code class="docutils literal notranslate">0</code> in isolated config.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.coerce_c_locale">
int coerce_c_locale<a class="headerlink" href="#c.PyPreConfig.coerce_c_locale" title="Permalink to this definition">¶</a> </dt>
<dd>If equals to 2, coerce the C locale.
If equals to 1, read the LC_CTYPE locale to decide if it should be
coerced.
See the <a class="reference internal" href="../glossary.html#term-locale-encoding">locale encoding</a>.
Default: <code class="docutils literal notranslate">-1</code> in Python config, <code class="docutils literal notranslate">0</code> in isolated config.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.coerce_c_locale_warn">
int coerce_c_locale_warn<a class="headerlink" href="#c.PyPreConfig.coerce_c_locale_warn" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, emit a warning if the C locale is coerced.
Default: <code class="docutils literal notranslate">-1</code> in Python config, <code class="docutils literal notranslate">0</code> in isolated config.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.dev_mode">
int dev_mode<a class="headerlink" href="#c.PyPreConfig.dev_mode" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, enables the <a class="reference internal" href="../library/devmode.html#devmode">Python Development Mode</a>:
see <a class="reference internal" href="#c.PyConfig.dev_mode" title="PyConfig.dev_mode"><code class="xref c c-member docutils literal notranslate">PyConfig.dev_mode</code></a>.
Default: <code class="docutils literal notranslate">-1</code> in Python mode, <code class="docutils literal notranslate">0</code> in isolated mode.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.isolated">
int isolated<a class="headerlink" href="#c.PyPreConfig.isolated" title="Permalink to this definition">¶</a> </dt>
<dd>Isolated mode: see <a class="reference internal" href="#c.PyConfig.isolated" title="PyConfig.isolated"><code class="xref c c-member docutils literal notranslate">PyConfig.isolated</code></a>.
Default: <code class="docutils literal notranslate">0</code> in Python mode, <code class="docutils literal notranslate">1</code> in isolated mode.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.legacy_windows_fs_encoding">
int legacy_windows_fs_encoding<a class="headerlink" href="#c.PyPreConfig.legacy_windows_fs_encoding" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero:
<ul class="simple">
<li>Set <a class="reference internal" href="#c.PyPreConfig.utf8_mode" title="PyPreConfig.utf8_mode"><code class="xref c c-member docutils literal notranslate">PyPreConfig.utf8_mode</code></a> to <code class="docutils literal notranslate">0</code>,</li>
<li>Set <a class="reference internal" href="#c.PyConfig.filesystem_encoding" title="PyConfig.filesystem_encoding"><code class="xref c c-member docutils literal notranslate">PyConfig.filesystem_encoding</code></a> to <code class="docutils literal notranslate">&quot;mbcs&quot;</code>,</li>
<li>Set <a class="reference internal" href="#c.PyConfig.filesystem_errors" title="PyConfig.filesystem_errors"><code class="xref c c-member docutils literal notranslate">PyConfig.filesystem_errors</code></a> to <code class="docutils literal notranslate">&quot;replace&quot;</code>.</li>
</ul>
Initialized the from <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONLEGACYWINDOWSFSENCODING"><code class="xref std std-envvar docutils literal notranslate">PYTHONLEGACYWINDOWSFSENCODING</code></a> environment
variable value.
Only available on Windows. <code class="docutils literal notranslate">#ifdef MS_WINDOWS</code> macro can be used for
Windows specific code.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.parse_argv">
int parse_argv<a class="headerlink" href="#c.PyPreConfig.parse_argv" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, <a class="reference internal" href="#c.Py_PreInitializeFromArgs" title="Py_PreInitializeFromArgs"><code class="xref c c-func docutils literal notranslate">Py_PreInitializeFromArgs()</code></a> and
<a class="reference internal" href="#c.Py_PreInitializeFromBytesArgs" title="Py_PreInitializeFromBytesArgs"><code class="xref c c-func docutils literal notranslate">Py_PreInitializeFromBytesArgs()</code></a> parse their <code class="docutils literal notranslate">argv</code> argument the
same way the regular Python parses command line arguments: see
<a class="reference internal" href="../using/cmdline.html#using-on-cmdline">Command Line Arguments</a>.
Default: <code class="docutils literal notranslate">1</code> in Python config, <code class="docutils literal notranslate">0</code> in isolated config.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.use_environment">
int use_environment<a class="headerlink" href="#c.PyPreConfig.use_environment" title="Permalink to this definition">¶</a> </dt>
<dd>Use <a class="reference internal" href="../using/cmdline.html#using-on-envvars">environment variables</a>? See
<a class="reference internal" href="#c.PyConfig.use_environment" title="PyConfig.use_environment"><code class="xref c c-member docutils literal notranslate">PyConfig.use_environment</code></a>.
Default: <code class="docutils literal notranslate">1</code> in Python config and <code class="docutils literal notranslate">0</code> in isolated config.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyPreConfig.utf8_mode">
int utf8_mode<a class="headerlink" href="#c.PyPreConfig.utf8_mode" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, enable the <a class="reference internal" href="../library/os.html#utf8-mode">Python UTF-8 Mode</a>.
Set by the <a class="reference internal" href="../using/cmdline.html#cmdoption-X"><code class="xref std std-option docutils literal notranslate">-X utf8</code></a> command line option and the
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONUTF8"><code class="xref std std-envvar docutils literal notranslate">PYTHONUTF8</code></a> environment variable.
Default: <code class="docutils literal notranslate">-1</code> in Python config and <code class="docutils literal notranslate">0</code> in isolated config.
</dd></dl>

</dd></dl>

</section>
<section id="preinitialize-python-with-pypreconfig">
<h2>Preinitialize Python with PyPreConfig<a class="headerlink" href="#preinitialize-python-with-pypreconfig" title="Permalink to this headline">¶</a></h2>
The preinitialization of Python:
<ul class="simple">
<li>Set the Python memory allocators (<a class="reference internal" href="#c.PyPreConfig.allocator" title="PyPreConfig.allocator"><code class="xref c c-member docutils literal notranslate">PyPreConfig.allocator</code></a>)</li>
<li>Configure the LC_CTYPE locale (<a class="reference internal" href="../glossary.html#term-locale-encoding">locale encoding</a>)</li>
<li>Set the <a class="reference internal" href="../library/os.html#utf8-mode">Python UTF-8 Mode</a>
(<a class="reference internal" href="#c.PyPreConfig.utf8_mode" title="PyPreConfig.utf8_mode"><code class="xref c c-member docutils literal notranslate">PyPreConfig.utf8_mode</code></a>)</li>
</ul>
The current preconfiguration (<code class="docutils literal notranslate">PyPreConfig</code> type) is stored in
<code class="docutils literal notranslate">_PyRuntime.preconfig</code>.
Functions to preinitialize Python:
<dl class="c function">
<dt class="sig sig-object c" id="c.Py_PreInitialize">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> Py_PreInitialize(const <a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig">PyPreConfig</a> *preconfig)<a class="headerlink" href="#c.Py_PreInitialize" title="Permalink to this definition">¶</a> </dt>
<dd>Preinitialize Python from preconfig preconfiguration.
preconfig must not be <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.Py_PreInitializeFromBytesArgs">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> Py_PreInitializeFromBytesArgs(const <a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig">PyPreConfig</a> *preconfig, int argc, char *const *argv)<a class="headerlink" href="#c.Py_PreInitializeFromBytesArgs" title="Permalink to this definition">¶</a> </dt>
<dd>Preinitialize Python from preconfig preconfiguration.
Parse argv command line arguments (bytes strings) if
<a class="reference internal" href="#c.PyPreConfig.parse_argv" title="PyPreConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">parse_argv</code></a> of preconfig is non-zero.
preconfig must not be <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.Py_PreInitializeFromArgs">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> Py_PreInitializeFromArgs(const <a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig">PyPreConfig</a> *preconfig, int argc, wchar_t *const *argv)<a class="headerlink" href="#c.Py_PreInitializeFromArgs" title="Permalink to this definition">¶</a> </dt>
<dd>Preinitialize Python from preconfig preconfiguration.
Parse argv command line arguments (wide strings) if
<a class="reference internal" href="#c.PyPreConfig.parse_argv" title="PyPreConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">parse_argv</code></a> of preconfig is non-zero.
preconfig must not be <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

The caller is responsible to handle exceptions (error or exit) using
<code class="xref c c-func docutils literal notranslate">PyStatus_Exception()</code> and <code class="xref c c-func docutils literal notranslate">Py_ExitStatusException()</code>.
For <a class="reference internal" href="#init-python-config">Python Configuration</a>
(<code class="xref c c-func docutils literal notranslate">PyPreConfig_InitPythonConfig()</code>), if Python is initialized with
command line arguments, the command line arguments must also be passed to
preinitialize Python, since they have an effect on the pre-configuration
like encodings. For example, the <a class="reference internal" href="../using/cmdline.html#cmdoption-X"><code class="xref std std-option docutils literal notranslate">-X utf8</code></a> command line option
enables the <a class="reference internal" href="../library/os.html#utf8-mode">Python UTF-8 Mode</a>.
<code class="docutils literal notranslate">PyMem_SetAllocator()</code> can be called after <a class="reference internal" href="#c.Py_PreInitialize" title="Py_PreInitialize"><code class="xref c c-func docutils literal notranslate">Py_PreInitialize()</code></a> and
before <a class="reference internal" href="#c.Py_InitializeFromConfig" title="Py_InitializeFromConfig"><code class="xref c c-func docutils literal notranslate">Py_InitializeFromConfig()</code></a> to install a custom memory allocator.
It can be called before <a class="reference internal" href="#c.Py_PreInitialize" title="Py_PreInitialize"><code class="xref c c-func docutils literal notranslate">Py_PreInitialize()</code></a> if
<a class="reference internal" href="#c.PyPreConfig.allocator" title="PyPreConfig.allocator"><code class="xref c c-member docutils literal notranslate">PyPreConfig.allocator</code></a> is set to <code class="docutils literal notranslate">PYMEM_ALLOCATOR_NOT_SET</code>.
Python memory allocation functions like <a class="reference internal" href="memory.html#c.PyMem_RawMalloc" title="PyMem_RawMalloc"><code class="xref c c-func docutils literal notranslate">PyMem_RawMalloc()</code></a> must not be
used before the Python preinitialization, whereas calling directly <code class="docutils literal notranslate">malloc()</code>
and <code class="docutils literal notranslate">free()</code> is always safe. <a class="reference internal" href="sys.html#c.Py_DecodeLocale" title="Py_DecodeLocale"><code class="xref c c-func docutils literal notranslate">Py_DecodeLocale()</code></a> must not be called
before the Python preinitialization.
Example using the preinitialization to enable
the <a class="reference internal" href="../library/os.html#utf8-mode">Python UTF-8 Mode</a>:
<div class="highlight-c notranslate"><div class="highlight"><pre>PyStatus status;
PyPreConfig preconfig;
PyPreConfig_InitPythonConfig(&amp;preconfig);

preconfig.utf8_mode = 1;

status = Py_PreInitialize(&amp;preconfig);
if (PyStatus_Exception(status)) {
 Py_ExitStatusException(status);
}

/* at this point, Python speaks UTF-8 */

Py_Initialize();
/* ... use Python API here ... */
Py_Finalize();
</pre></div>
</div>
</section>
<section id="pyconfig">
<h2>PyConfig<a class="headerlink" href="#pyconfig" title="Permalink to this headline">¶</a></h2>
<dl class="c type">
<dt class="sig sig-object c" id="c.PyConfig">
type PyConfig<a class="headerlink" href="#c.PyConfig" title="Permalink to this definition">¶</a> </dt>
<dd>Structure containing most parameters to configure Python.
When done, the <a class="reference internal" href="#c.PyConfig.PyConfig_Clear" title="PyConfig_Clear"><code class="xref c c-func docutils literal notranslate">PyConfig_Clear()</code></a> function must be used to release the
configuration memory.
Structure methods:
<dl class="c function">
<dt class="sig sig-object c" id="c.PyConfig.PyConfig_InitPythonConfig">
void PyConfig_InitPythonConfig(<a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config)<a class="headerlink" href="#c.PyConfig.PyConfig_InitPythonConfig" title="Permalink to this definition">¶</a> </dt>
<dd>Initialize configuration with the <a class="reference internal" href="#init-python-config">Python Configuration</a>.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyConfig.PyConfig_InitIsolatedConfig">
void PyConfig_InitIsolatedConfig(<a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config)<a class="headerlink" href="#c.PyConfig.PyConfig_InitIsolatedConfig" title="Permalink to this definition">¶</a> </dt>
<dd>Initialize configuration with the <a class="reference internal" href="#init-isolated-conf">Isolated Configuration</a>.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyConfig.PyConfig_SetString">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyConfig_SetString(<a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config, wchar_t *const *config_str, const wchar_t *str)<a class="headerlink" href="#c.PyConfig.PyConfig_SetString" title="Permalink to this definition">¶</a> </dt>
<dd>Copy the wide character string str into <code class="docutils literal notranslate">*config_str</code>.
<a class="reference internal" href="#c-preinit">Preinitialize Python</a> if needed.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyConfig.PyConfig_SetBytesString">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyConfig_SetBytesString(<a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config, wchar_t *const *config_str, const char *str)<a class="headerlink" href="#c.PyConfig.PyConfig_SetBytesString" title="Permalink to this definition">¶</a> </dt>
<dd>Decode str using <a class="reference internal" href="sys.html#c.Py_DecodeLocale" title="Py_DecodeLocale"><code class="xref c c-func docutils literal notranslate">Py_DecodeLocale()</code></a> and set the result into
<code class="docutils literal notranslate">*config_str</code>.
<a class="reference internal" href="#c-preinit">Preinitialize Python</a> if needed.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyConfig.PyConfig_SetArgv">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyConfig_SetArgv(<a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config, int argc, wchar_t *const *argv)<a class="headerlink" href="#c.PyConfig.PyConfig_SetArgv" title="Permalink to this definition">¶</a> </dt>
<dd>Set command line arguments (<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> member of
config) from the argv list of wide character strings.
<a class="reference internal" href="#c-preinit">Preinitialize Python</a> if needed.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyConfig.PyConfig_SetBytesArgv">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyConfig_SetBytesArgv(<a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config, int argc, char *const *argv)<a class="headerlink" href="#c.PyConfig.PyConfig_SetBytesArgv" title="Permalink to this definition">¶</a> </dt>
<dd>Set command line arguments (<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> member of
config) from the argv list of bytes strings. Decode bytes using
<a class="reference internal" href="sys.html#c.Py_DecodeLocale" title="Py_DecodeLocale"><code class="xref c c-func docutils literal notranslate">Py_DecodeLocale()</code></a>.
<a class="reference internal" href="#c-preinit">Preinitialize Python</a> if needed.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyConfig.PyConfig_SetWideStringList">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyConfig_SetWideStringList(<a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config, <a class="reference internal" href="#c.PyWideStringList" title="PyWideStringList">PyWideStringList</a> *list, <a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t">Py_ssize_t</a> length, wchar_t **items)<a class="headerlink" href="#c.PyConfig.PyConfig_SetWideStringList" title="Permalink to this definition">¶</a> </dt>
<dd>Set the list of wide strings list to length and items.
<a class="reference internal" href="#c-preinit">Preinitialize Python</a> if needed.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyConfig.PyConfig_Read">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> PyConfig_Read(<a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config)<a class="headerlink" href="#c.PyConfig.PyConfig_Read" title="Permalink to this definition">¶</a> </dt>
<dd>Read all Python configuration.
Fields which are already initialized are left unchanged.
The <a class="reference internal" href="#c.PyConfig.PyConfig_Read" title="PyConfig_Read"><code class="xref c c-func docutils literal notranslate">PyConfig_Read()</code></a> function only parses
<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">PyConfig.argv</code></a> arguments once: <a class="reference internal" href="#c.PyConfig.parse_argv" title="PyConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">PyConfig.parse_argv</code></a>
is set to <code class="docutils literal notranslate">2</code> after arguments are parsed. Since Python arguments are
strippped from <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">PyConfig.argv</code></a>, parsing arguments twice would
parse the application options as Python options.
<a class="reference internal" href="#c-preinit">Preinitialize Python</a> if needed.
<div class="versionchanged">
Changed in version 3.10: The <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">PyConfig.argv</code></a> arguments are now only parsed once,
<a class="reference internal" href="#c.PyConfig.parse_argv" title="PyConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">PyConfig.parse_argv</code></a> is set to <code class="docutils literal notranslate">2</code> after arguments are
parsed, and arguments are only parsed if
<a class="reference internal" href="#c.PyConfig.parse_argv" title="PyConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">PyConfig.parse_argv</code></a> equals <code class="docutils literal notranslate">1</code>.
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyConfig.PyConfig_Clear">
void PyConfig_Clear(<a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config)<a class="headerlink" href="#c.PyConfig.PyConfig_Clear" title="Permalink to this definition">¶</a> </dt>
<dd>Release configuration memory.
</dd></dl>

Most <code class="docutils literal notranslate">PyConfig</code> methods <a class="reference internal" href="#c-preinit">preinitialize Python</a> if needed.
In that case, the Python preinitialization configuration
(<a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig"><code class="xref c c-type docutils literal notranslate">PyPreConfig</code></a>) in based on the <a class="reference internal" href="#c.PyConfig" title="PyConfig"><code class="xref c c-type docutils literal notranslate">PyConfig</code></a>. If configuration
fields which are in common with <a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig"><code class="xref c c-type docutils literal notranslate">PyPreConfig</code></a> are tuned, they must
be set before calling a <a class="reference internal" href="#c.PyConfig" title="PyConfig"><code class="xref c c-type docutils literal notranslate">PyConfig</code></a> method:
<ul class="simple">
<li><a class="reference internal" href="#c.PyConfig.dev_mode" title="PyConfig.dev_mode"><code class="xref c c-member docutils literal notranslate">PyConfig.dev_mode</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.isolated" title="PyConfig.isolated"><code class="xref c c-member docutils literal notranslate">PyConfig.isolated</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.parse_argv" title="PyConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">PyConfig.parse_argv</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.use_environment" title="PyConfig.use_environment"><code class="xref c c-member docutils literal notranslate">PyConfig.use_environment</code></a></li>
</ul>
Moreover, if <a class="reference internal" href="#c.PyConfig.PyConfig_SetArgv" title="PyConfig_SetArgv"><code class="xref c c-func docutils literal notranslate">PyConfig_SetArgv()</code></a> or <a class="reference internal" href="#c.PyConfig.PyConfig_SetBytesArgv" title="PyConfig_SetBytesArgv"><code class="xref c c-func docutils literal notranslate">PyConfig_SetBytesArgv()</code></a>
is used, this method must be called before other methods, since the
preinitialization configuration depends on command line arguments (if
<a class="reference internal" href="#c.PyConfig.parse_argv" title="parse_argv"><code class="xref c c-member docutils literal notranslate">parse_argv</code></a> is non-zero).
The caller of these methods is responsible to handle exceptions (error or
exit) using <code class="docutils literal notranslate">PyStatus_Exception()</code> and <code class="docutils literal notranslate">Py_ExitStatusException()</code>.
Structure fields:
<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.argv">
<a class="reference internal" href="#c.PyWideStringList" title="PyWideStringList">PyWideStringList</a> argv<a class="headerlink" href="#c.PyConfig.argv" title="Permalink to this definition">¶</a> </dt>
<dd>Command line arguments: <a class="reference internal" href="../library/sys.html#sys.argv" title="sys.argv"><code class="xref py py-data docutils literal notranslate">sys.argv</code></a>.
Set <a class="reference internal" href="#c.PyConfig.parse_argv" title="PyConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">parse_argv</code></a> to <code class="docutils literal notranslate">1</code> to parse
<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> the same way the regular Python parses Python
command line arguments and then to strip Python arguments from
<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a>.
If <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> is empty, an empty string is added to
ensure that <a class="reference internal" href="../library/sys.html#sys.argv" title="sys.argv"><code class="xref py py-data docutils literal notranslate">sys.argv</code></a> always exists and is never empty.
Default: <code class="docutils literal notranslate">NULL</code>.
See also the <a class="reference internal" href="#c.PyConfig.orig_argv" title="PyConfig.orig_argv"><code class="xref c c-member docutils literal notranslate">orig_argv</code></a> member.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.base_exec_prefix">
wchar_t *base_exec_prefix<a class="headerlink" href="#c.PyConfig.base_exec_prefix" title="Permalink to this definition">¶</a> </dt>
<dd><a class="reference internal" href="../library/sys.html#sys.base_exec_prefix" title="sys.base_exec_prefix"><code class="xref py py-data docutils literal notranslate">sys.base_exec_prefix</code></a>.
Default: <code class="docutils literal notranslate">NULL</code>.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> output.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.base_executable">
wchar_t *base_executable<a class="headerlink" href="#c.PyConfig.base_executable" title="Permalink to this definition">¶</a> </dt>
<dd>Python base executable: <code class="xref py py-data docutils literal notranslate">sys._base_executable</code>.
Set by the <code class="xref std std-envvar docutils literal notranslate">__PYVENV_LAUNCHER__</code> environment variable.
Set from <a class="reference internal" href="#c.PyConfig.executable" title="PyConfig.executable"><code class="xref c c-member docutils literal notranslate">PyConfig.executable</code></a> if <code class="docutils literal notranslate">NULL</code>.
Default: <code class="docutils literal notranslate">NULL</code>.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> output.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.base_prefix">
wchar_t *base_prefix<a class="headerlink" href="#c.PyConfig.base_prefix" title="Permalink to this definition">¶</a> </dt>
<dd><a class="reference internal" href="../library/sys.html#sys.base_prefix" title="sys.base_prefix"><code class="xref py py-data docutils literal notranslate">sys.base_prefix</code></a>.
Default: <code class="docutils literal notranslate">NULL</code>.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> output.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.buffered_stdio">
int buffered_stdio<a class="headerlink" href="#c.PyConfig.buffered_stdio" title="Permalink to this definition">¶</a> </dt>
<dd>If equals to 0 and <a class="reference internal" href="#c.PyConfig.configure_c_stdio" title="PyConfig.configure_c_stdio"><code class="xref c c-member docutils literal notranslate">configure_c_stdio</code></a> is non-zero,
disable buffering on the C streams stdout and stderr.
Set to 0 by the <a class="reference internal" href="../using/cmdline.html#cmdoption-u"><code class="xref std std-option docutils literal notranslate">-u</code></a> command line option and the
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONUNBUFFERED"><code class="xref std std-envvar docutils literal notranslate">PYTHONUNBUFFERED</code></a> environment variable.
stdin is always opened in buffered mode.
Default: <code class="docutils literal notranslate">1</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.bytes_warning">
int bytes_warning<a class="headerlink" href="#c.PyConfig.bytes_warning" title="Permalink to this definition">¶</a> </dt>
<dd>If equals to 1, issue a warning when comparing <a class="reference internal" href="../library/stdtypes.html#bytes" title="bytes"><code class="xref py py-class docutils literal notranslate">bytes</code></a> or
<a class="reference internal" href="../library/stdtypes.html#bytearray" title="bytearray"><code class="xref py py-class docutils literal notranslate">bytearray</code></a> with <a class="reference internal" href="../library/stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate">str</code></a>, or comparing <a class="reference internal" href="../library/stdtypes.html#bytes" title="bytes"><code class="xref py py-class docutils literal notranslate">bytes</code></a> with
<a class="reference internal" href="../library/functions.html#int" title="int"><code class="xref py py-class docutils literal notranslate">int</code></a>.
If equal or greater to 2, raise a <a class="reference internal" href="../library/exceptions.html#BytesWarning" title="BytesWarning"><code class="xref py py-exc docutils literal notranslate">BytesWarning</code></a> exception in these
cases.
Incremented by the <a class="reference internal" href="../using/cmdline.html#cmdoption-b"><code class="xref std std-option docutils literal notranslate">-b</code></a> command line option.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.warn_default_encoding">
int warn_default_encoding<a class="headerlink" href="#c.PyConfig.warn_default_encoding" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, emit a <a class="reference internal" href="../library/exceptions.html#EncodingWarning" title="EncodingWarning"><code class="xref py py-exc docutils literal notranslate">EncodingWarning</code></a> warning when <a class="reference internal" href="../library/io.html#io.TextIOWrapper" title="io.TextIOWrapper"><code class="xref py py-class docutils literal notranslate">io.TextIOWrapper</code></a>
uses its default encoding. See <a class="reference internal" href="../library/io.html#io-encoding-warning">Opt-in EncodingWarning</a> for details.
Default: <code class="docutils literal notranslate">0</code>.
<div class="versionadded">
New in version 3.10.
</div>
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.check_hash_pycs_mode">
wchar_t *check_hash_pycs_mode<a class="headerlink" href="#c.PyConfig.check_hash_pycs_mode" title="Permalink to this definition">¶</a> </dt>
<dd>Control the validation behavior of hash-based <code class="docutils literal notranslate">.pyc</code> files:
value of the <a class="reference internal" href="../using/cmdline.html#cmdoption-check-hash-based-pycs"><code class="xref std std-option docutils literal notranslate">--check-hash-based-pycs</code></a> command line option.
Valid values:
<ul class="simple">
<li><code class="docutils literal notranslate">L&quot;always&quot;</code>: Hash the source file for invalidation regardless of
value of the ‘check_source’ flag.</li>
<li><code class="docutils literal notranslate">L&quot;never&quot;</code>: Assume that hash-based pycs always are valid.</li>
<li><code class="docutils literal notranslate">L&quot;default&quot;</code>: The ‘check_source’ flag in hash-based pycs
determines invalidation.</li>
</ul>
Default: <code class="docutils literal notranslate">L&quot;default&quot;</code>.
See also <a class="pep reference external" href="https://www.python.org/dev/peps/pep-0552">PEP 552</a> “Deterministic pycs”.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.configure_c_stdio">
int configure_c_stdio<a class="headerlink" href="#c.PyConfig.configure_c_stdio" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, configure C standard streams:
<ul class="simple">
<li>On Windows, set the binary mode (<code class="docutils literal notranslate">O_BINARY</code>) on stdin, stdout and
stderr.</li>
<li>If <a class="reference internal" href="#c.PyConfig.buffered_stdio" title="PyConfig.buffered_stdio"><code class="xref c c-member docutils literal notranslate">buffered_stdio</code></a> equals zero, disable buffering
of stdin, stdout and stderr streams.</li>
<li>If <a class="reference internal" href="#c.PyConfig.interactive" title="PyConfig.interactive"><code class="xref c c-member docutils literal notranslate">interactive</code></a> is non-zero, enable stream
buffering on stdin and stdout (only stdout on Windows).</li>
</ul>
Default: <code class="docutils literal notranslate">1</code> in Python config, <code class="docutils literal notranslate">0</code> in isolated config.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.dev_mode">
int dev_mode<a class="headerlink" href="#c.PyConfig.dev_mode" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, enable the <a class="reference internal" href="../library/devmode.html#devmode">Python Development Mode</a>.
Default: <code class="docutils literal notranslate">-1</code> in Python mode, <code class="docutils literal notranslate">0</code> in isolated mode.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.dump_refs">
int dump_refs<a class="headerlink" href="#c.PyConfig.dump_refs" title="Permalink to this definition">¶</a> </dt>
<dd>Dump Python references?
If non-zero, dump all objects which are still alive at exit.
Set to <code class="docutils literal notranslate">1</code> by the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONDUMPREFS"><code class="xref std std-envvar docutils literal notranslate">PYTHONDUMPREFS</code></a> environment variable.
Need a special build of Python with the <code class="docutils literal notranslate">Py_TRACE_REFS</code> macro defined:
see the <a class="reference internal" href="../using/configure.html#cmdoption-with-trace-refs"><code class="xref std std-option docutils literal notranslate">configure --with-trace-refs option</code></a>.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.exec_prefix">
wchar_t *exec_prefix<a class="headerlink" href="#c.PyConfig.exec_prefix" title="Permalink to this definition">¶</a> </dt>
<dd>The site-specific directory prefix where the platform-dependent Python
files are installed: <a class="reference internal" href="../library/sys.html#sys.exec_prefix" title="sys.exec_prefix"><code class="xref py py-data docutils literal notranslate">sys.exec_prefix</code></a>.
Default: <code class="docutils literal notranslate">NULL</code>.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> output.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.executable">
wchar_t *executable<a class="headerlink" href="#c.PyConfig.executable" title="Permalink to this definition">¶</a> </dt>
<dd>The absolute path of the executable binary for the Python interpreter:
<a class="reference internal" href="../library/sys.html#sys.executable" title="sys.executable"><code class="xref py py-data docutils literal notranslate">sys.executable</code></a>.
Default: <code class="docutils literal notranslate">NULL</code>.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> output.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.faulthandler">
int faulthandler<a class="headerlink" href="#c.PyConfig.faulthandler" title="Permalink to this definition">¶</a> </dt>
<dd>Enable faulthandler?
If non-zero, call <a class="reference internal" href="../library/faulthandler.html#faulthandler.enable" title="faulthandler.enable"><code class="xref py py-func docutils literal notranslate">faulthandler.enable()</code></a> at startup.
Set to <code class="docutils literal notranslate">1</code> by <a class="reference internal" href="../using/cmdline.html#cmdoption-X"><code class="xref std std-option docutils literal notranslate">-X faulthandler</code></a> and the
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONFAULTHANDLER"><code class="xref std std-envvar docutils literal notranslate">PYTHONFAULTHANDLER</code></a> environment variable.
Default: <code class="docutils literal notranslate">-1</code> in Python mode, <code class="docutils literal notranslate">0</code> in isolated mode.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.filesystem_encoding">
wchar_t *filesystem_encoding<a class="headerlink" href="#c.PyConfig.filesystem_encoding" title="Permalink to this definition">¶</a> </dt>
<dd><a class="reference internal" href="../glossary.html#term-filesystem-encoding-and-error-handler">Filesystem encoding</a>:
<a class="reference internal" href="../library/sys.html#sys.getfilesystemencoding" title="sys.getfilesystemencoding"><code class="xref py py-func docutils literal notranslate">sys.getfilesystemencoding()</code></a>.
On macOS, Android and VxWorks: use <code class="docutils literal notranslate">&quot;utf-8&quot;</code> by default.
On Windows: use <code class="docutils literal notranslate">&quot;utf-8&quot;</code> by default, or <code class="docutils literal notranslate">&quot;mbcs&quot;</code> if
<a class="reference internal" href="#c.PyPreConfig.legacy_windows_fs_encoding" title="PyPreConfig.legacy_windows_fs_encoding"><code class="xref c c-member docutils literal notranslate">legacy_windows_fs_encoding</code></a> of
<a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig"><code class="xref c c-type docutils literal notranslate">PyPreConfig</code></a> is non-zero.
Default encoding on other platforms:
<ul class="simple">
<li><code class="docutils literal notranslate">&quot;utf-8&quot;</code> if <a class="reference internal" href="#c.PyPreConfig.utf8_mode" title="PyPreConfig.utf8_mode"><code class="xref c c-member docutils literal notranslate">PyPreConfig.utf8_mode</code></a> is non-zero.</li>
<li><code class="docutils literal notranslate">&quot;ascii&quot;</code> if Python detects that <code class="docutils literal notranslate">nl_langinfo(CODESET)</code> announces
the ASCII encoding, whereas the <code class="docutils literal notranslate">mbstowcs()</code> function
decodes from a different encoding (usually Latin1).</li>
<li><code class="docutils literal notranslate">&quot;utf-8&quot;</code> if <code class="docutils literal notranslate">nl_langinfo(CODESET)</code> returns an empty string.</li>
<li>Otherwise, use the <a class="reference internal" href="../glossary.html#term-locale-encoding">locale encoding</a>:
<code class="docutils literal notranslate">nl_langinfo(CODESET)</code> result.</li>
</ul>
At Python startup, the encoding name is normalized to the Python codec
name. For example, <code class="docutils literal notranslate">&quot;ANSI_X3.4-1968&quot;</code> is replaced with <code class="docutils literal notranslate">&quot;ascii&quot;</code>.
See also the <a class="reference internal" href="#c.PyConfig.filesystem_errors" title="PyConfig.filesystem_errors"><code class="xref c c-member docutils literal notranslate">filesystem_errors</code></a> member.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.filesystem_errors">
wchar_t *filesystem_errors<a class="headerlink" href="#c.PyConfig.filesystem_errors" title="Permalink to this definition">¶</a> </dt>
<dd><a class="reference internal" href="../glossary.html#term-filesystem-encoding-and-error-handler">Filesystem error handler</a>:
<a class="reference internal" href="../library/sys.html#sys.getfilesystemencodeerrors" title="sys.getfilesystemencodeerrors"><code class="xref py py-func docutils literal notranslate">sys.getfilesystemencodeerrors()</code></a>.
On Windows: use <code class="docutils literal notranslate">&quot;surrogatepass&quot;</code> by default, or <code class="docutils literal notranslate">&quot;replace&quot;</code> if
<a class="reference internal" href="#c.PyPreConfig.legacy_windows_fs_encoding" title="PyPreConfig.legacy_windows_fs_encoding"><code class="xref c c-member docutils literal notranslate">legacy_windows_fs_encoding</code></a> of
<a class="reference internal" href="#c.PyPreConfig" title="PyPreConfig"><code class="xref c c-type docutils literal notranslate">PyPreConfig</code></a> is non-zero.
On other platforms: use <code class="docutils literal notranslate">&quot;surrogateescape&quot;</code> by default.
Supported error handlers:
<ul class="simple">
<li><code class="docutils literal notranslate">&quot;strict&quot;</code></li>
<li><code class="docutils literal notranslate">&quot;surrogateescape&quot;</code></li>
<li><code class="docutils literal notranslate">&quot;surrogatepass&quot;</code> (only supported with the UTF-8 encoding)</li>
</ul>
See also the <a class="reference internal" href="#c.PyConfig.filesystem_encoding" title="PyConfig.filesystem_encoding"><code class="xref c c-member docutils literal notranslate">filesystem_encoding</code></a> member.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.hash_seed">
unsigned long hash_seed<a class="headerlink" href="#c.PyConfig.hash_seed" title="Permalink to this definition">¶</a> </dt>
<dd></dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.use_hash_seed">
int use_hash_seed<a class="headerlink" href="#c.PyConfig.use_hash_seed" title="Permalink to this definition">¶</a> </dt>
<dd>Randomized hash function seed.
If <a class="reference internal" href="#c.PyConfig.use_hash_seed" title="PyConfig.use_hash_seed"><code class="xref c c-member docutils literal notranslate">use_hash_seed</code></a> is zero, a seed is chosen randomly
at Python startup, and <a class="reference internal" href="#c.PyConfig.hash_seed" title="PyConfig.hash_seed"><code class="xref c c-member docutils literal notranslate">hash_seed</code></a> is ignored.
Set by the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONHASHSEED"><code class="xref std std-envvar docutils literal notranslate">PYTHONHASHSEED</code></a> environment variable.
Default use_hash_seed value: <code class="docutils literal notranslate">-1</code> in Python mode, <code class="docutils literal notranslate">0</code> in isolated
mode.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.home">
wchar_t *home<a class="headerlink" href="#c.PyConfig.home" title="Permalink to this definition">¶</a> </dt>
<dd>Python home directory.
If <a class="reference internal" href="init.html#c.Py_SetPythonHome" title="Py_SetPythonHome"><code class="xref c c-func docutils literal notranslate">Py_SetPythonHome()</code></a> has been called, use its argument if it is
not <code class="docutils literal notranslate">NULL</code>.
Set by the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONHOME"><code class="xref std std-envvar docutils literal notranslate">PYTHONHOME</code></a> environment variable.
Default: <code class="docutils literal notranslate">NULL</code>.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> input.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.import_time">
int import_time<a class="headerlink" href="#c.PyConfig.import_time" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, profile import time.
Set the <code class="docutils literal notranslate">1</code> by the <a class="reference internal" href="../using/cmdline.html#cmdoption-X"><code class="xref std std-option docutils literal notranslate">-X importtime</code></a> option and the
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONPROFILEIMPORTTIME"><code class="xref std std-envvar docutils literal notranslate">PYTHONPROFILEIMPORTTIME</code></a> environment variable.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.inspect">
int inspect<a class="headerlink" href="#c.PyConfig.inspect" title="Permalink to this definition">¶</a> </dt>
<dd>Enter interactive mode after executing a script or a command.
If greater than 0, enable inspect: when a script is passed as first
argument or the -c option is used, enter interactive mode after executing
the script or the command, even when <a class="reference internal" href="../library/sys.html#sys.stdin" title="sys.stdin"><code class="xref py py-data docutils literal notranslate">sys.stdin</code></a> does not appear to
be a terminal.
Incremented by the <a class="reference internal" href="../using/cmdline.html#cmdoption-i"><code class="xref std std-option docutils literal notranslate">-i</code></a> command line option. Set to <code class="docutils literal notranslate">1</code> if the
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONINSPECT"><code class="xref std std-envvar docutils literal notranslate">PYTHONINSPECT</code></a> environment variable is non-empty.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.install_signal_handlers">
int install_signal_handlers<a class="headerlink" href="#c.PyConfig.install_signal_handlers" title="Permalink to this definition">¶</a> </dt>
<dd>Install Python signal handlers?
Default: <code class="docutils literal notranslate">1</code> in Python mode, <code class="docutils literal notranslate">0</code> in isolated mode.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.interactive">
int interactive<a class="headerlink" href="#c.PyConfig.interactive" title="Permalink to this definition">¶</a> </dt>
<dd>If greater than 0, enable the interactive mode (REPL).
Incremented by the <a class="reference internal" href="../using/cmdline.html#cmdoption-i"><code class="xref std std-option docutils literal notranslate">-i</code></a> command line option.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.isolated">
int isolated<a class="headerlink" href="#c.PyConfig.isolated" title="Permalink to this definition">¶</a> </dt>
<dd>If greater than 0, enable isolated mode:
<ul class="simple">
<li><a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a> contains neither the script’s directory (computed from
<code class="docutils literal notranslate">argv[0]</code> or the current directory) nor the user’s site-packages
directory.</li>
<li>Python REPL doesn’t import <a class="reference internal" href="../library/readline.html#module-readline" title="readline: GNU readline support for Python. (Unix)"><code class="xref py py-mod docutils literal notranslate">readline</code></a> nor enable default readline
configuration on interactive prompts.</li>
<li>Set <a class="reference internal" href="#c.PyConfig.use_environment" title="PyConfig.use_environment"><code class="xref c c-member docutils literal notranslate">use_environment</code></a> and
<a class="reference internal" href="#c.PyConfig.user_site_directory" title="PyConfig.user_site_directory"><code class="xref c c-member docutils literal notranslate">user_site_directory</code></a> to 0.</li>
</ul>
Default: <code class="docutils literal notranslate">0</code> in Python mode, <code class="docutils literal notranslate">1</code> in isolated mode.
See also <a class="reference internal" href="#c.PyPreConfig.isolated" title="PyPreConfig.isolated"><code class="xref c c-member docutils literal notranslate">PyPreConfig.isolated</code></a>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.legacy_windows_stdio">
int legacy_windows_stdio<a class="headerlink" href="#c.PyConfig.legacy_windows_stdio" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, use <a class="reference internal" href="../library/io.html#io.FileIO" title="io.FileIO"><code class="xref py py-class docutils literal notranslate">io.FileIO</code></a> instead of
<code class="xref py py-class docutils literal notranslate">io.WindowsConsoleIO</code> for <a class="reference internal" href="../library/sys.html#sys.stdin" title="sys.stdin"><code class="xref py py-data docutils literal notranslate">sys.stdin</code></a>, <a class="reference internal" href="../library/sys.html#sys.stdout" title="sys.stdout"><code class="xref py py-data docutils literal notranslate">sys.stdout</code></a>
and <a class="reference internal" href="../library/sys.html#sys.stderr" title="sys.stderr"><code class="xref py py-data docutils literal notranslate">sys.stderr</code></a>.
Set to <code class="docutils literal notranslate">1</code> if the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONLEGACYWINDOWSSTDIO"><code class="xref std std-envvar docutils literal notranslate">PYTHONLEGACYWINDOWSSTDIO</code></a> environment
variable is set to a non-empty string.
Only available on Windows. <code class="docutils literal notranslate">#ifdef MS_WINDOWS</code> macro can be used for
Windows specific code.
Default: <code class="docutils literal notranslate">0</code>.
See also the <a class="pep reference external" href="https://www.python.org/dev/peps/pep-0528">PEP 528</a> (Change Windows console encoding to UTF-8).
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.malloc_stats">
int malloc_stats<a class="headerlink" href="#c.PyConfig.malloc_stats" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, dump statistics on <a class="reference internal" href="memory.html#pymalloc">Python pymalloc memory allocator</a> at exit.
Set to <code class="docutils literal notranslate">1</code> by the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONMALLOCSTATS"><code class="xref std std-envvar docutils literal notranslate">PYTHONMALLOCSTATS</code></a> environment variable.
The option is ignored if Python is <a class="reference internal" href="../using/configure.html#cmdoption-without-pymalloc"><code class="xref std std-option docutils literal notranslate">configured using
the --without-pymalloc option</code></a>.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.platlibdir">
wchar_t *platlibdir<a class="headerlink" href="#c.PyConfig.platlibdir" title="Permalink to this definition">¶</a> </dt>
<dd>Platform library directory name: <a class="reference internal" href="../library/sys.html#sys.platlibdir" title="sys.platlibdir"><code class="xref py py-data docutils literal notranslate">sys.platlibdir</code></a>.
Set by the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONPLATLIBDIR"><code class="xref std std-envvar docutils literal notranslate">PYTHONPLATLIBDIR</code></a> environment variable.
Default: value of the <code class="docutils literal notranslate">PLATLIBDIR</code> macro which is set by the
<a class="reference internal" href="../using/configure.html#cmdoption-with-platlibdir"><code class="xref std std-option docutils literal notranslate">configure --with-platlibdir option</code></a>
(default: <code class="docutils literal notranslate">&quot;lib&quot;</code>).
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> input.
<div class="versionadded">
New in version 3.9.
</div>
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.pythonpath_env">
wchar_t *pythonpath_env<a class="headerlink" href="#c.PyConfig.pythonpath_env" title="Permalink to this definition">¶</a> </dt>
<dd>Module search paths (<a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>) as a string separated by <code class="docutils literal notranslate">DELIM</code>
(<code class="xref py py-data docutils literal notranslate">os.path.pathsep</code>).
Set by the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONPATH"><code class="xref std std-envvar docutils literal notranslate">PYTHONPATH</code></a> environment variable.
Default: <code class="docutils literal notranslate">NULL</code>.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> input.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.module_search_paths">
<a class="reference internal" href="#c.PyWideStringList" title="PyWideStringList">PyWideStringList</a> module_search_paths<a class="headerlink" href="#c.PyConfig.module_search_paths" title="Permalink to this definition">¶</a> </dt>
<dd></dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.module_search_paths_set">
int module_search_paths_set<a class="headerlink" href="#c.PyConfig.module_search_paths_set" title="Permalink to this definition">¶</a> </dt>
<dd>Module search paths: <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>.
If <a class="reference internal" href="#c.PyConfig.module_search_paths_set" title="PyConfig.module_search_paths_set"><code class="xref c c-member docutils literal notranslate">module_search_paths_set</code></a> is equal to 0, the
function calculating the <a class="reference internal" href="#init-path-config">Python Path Configuration</a>
overrides the <a class="reference internal" href="#c.PyConfig.module_search_paths" title="PyConfig.module_search_paths"><code class="xref c c-member docutils literal notranslate">module_search_paths</code></a> and sets
<a class="reference internal" href="#c.PyConfig.module_search_paths_set" title="PyConfig.module_search_paths_set"><code class="xref c c-member docutils literal notranslate">module_search_paths_set</code></a> to <code class="docutils literal notranslate">1</code>.
Default: empty list (<code class="docutils literal notranslate">module_search_paths</code>) and <code class="docutils literal notranslate">0</code>
(<code class="docutils literal notranslate">module_search_paths_set</code>).
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> output.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.optimization_level">
int optimization_level<a class="headerlink" href="#c.PyConfig.optimization_level" title="Permalink to this definition">¶</a> </dt>
<dd>Compilation optimization level:
<ul class="simple">
<li><code class="docutils literal notranslate">0</code>: Peephole optimizer, set <code class="docutils literal notranslate">__debug__</code> to <code class="docutils literal notranslate">True</code>.</li>
<li><code class="docutils literal notranslate">1</code>: Level 0, remove assertions, set <code class="docutils literal notranslate">__debug__</code> to <code class="docutils literal notranslate">False</code>.</li>
<li><code class="docutils literal notranslate">2</code>: Level 1, strip docstrings.</li>
</ul>
Incremented by the <a class="reference internal" href="../using/cmdline.html#cmdoption-O"><code class="xref std std-option docutils literal notranslate">-O</code></a> command line option. Set to the
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONOPTIMIZE"><code class="xref std std-envvar docutils literal notranslate">PYTHONOPTIMIZE</code></a> environment variable value.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.orig_argv">
<a class="reference internal" href="#c.PyWideStringList" title="PyWideStringList">PyWideStringList</a> orig_argv<a class="headerlink" href="#c.PyConfig.orig_argv" title="Permalink to this definition">¶</a> </dt>
<dd>The list of the original command line arguments passed to the Python
executable: <a class="reference internal" href="../library/sys.html#sys.orig_argv" title="sys.orig_argv"><code class="xref py py-data docutils literal notranslate">sys.orig_argv</code></a>.
If <a class="reference internal" href="#c.PyConfig.orig_argv" title="PyConfig.orig_argv"><code class="xref c c-member docutils literal notranslate">orig_argv</code></a> list is empty and
<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> is not a list only containing an empty
string, <a class="reference internal" href="#c.PyConfig.PyConfig_Read" title="PyConfig_Read"><code class="xref c c-func docutils literal notranslate">PyConfig_Read()</code></a> copies <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> into
<a class="reference internal" href="#c.PyConfig.orig_argv" title="PyConfig.orig_argv"><code class="xref c c-member docutils literal notranslate">orig_argv</code></a> before modifying
<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> (if <a class="reference internal" href="#c.PyConfig.parse_argv" title="PyConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">parse_argv</code></a> is
non-zero).
See also the <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> member and the
<a class="reference internal" href="#c.Py_GetArgcArgv" title="Py_GetArgcArgv"><code class="xref c c-func docutils literal notranslate">Py_GetArgcArgv()</code></a> function.
Default: empty list.
<div class="versionadded">
New in version 3.10.
</div>
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.parse_argv">
int parse_argv<a class="headerlink" href="#c.PyConfig.parse_argv" title="Permalink to this definition">¶</a> </dt>
<dd>Parse command line arguments?
If equals to <code class="docutils literal notranslate">1</code>, parse <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> the same way the regular
Python parses <a class="reference internal" href="../using/cmdline.html#using-on-cmdline">command line arguments</a>, and strip
Python arguments from <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a>.
The <a class="reference internal" href="#c.PyConfig.PyConfig_Read" title="PyConfig_Read"><code class="xref c c-func docutils literal notranslate">PyConfig_Read()</code></a> function only parses
<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">PyConfig.argv</code></a> arguments once: <a class="reference internal" href="#c.PyConfig.parse_argv" title="PyConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">PyConfig.parse_argv</code></a>
is set to <code class="docutils literal notranslate">2</code> after arguments are parsed. Since Python arguments are
strippped from <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">PyConfig.argv</code></a>, parsing arguments twice would
parse the application options as Python options.
Default: <code class="docutils literal notranslate">1</code> in Python mode, <code class="docutils literal notranslate">0</code> in isolated mode.
<div class="versionchanged">
Changed in version 3.10: The <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">PyConfig.argv</code></a> arguments are now only parsed if
<a class="reference internal" href="#c.PyConfig.parse_argv" title="PyConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">PyConfig.parse_argv</code></a> equals to <code class="docutils literal notranslate">1</code>.
</div>
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.parser_debug">
int parser_debug<a class="headerlink" href="#c.PyConfig.parser_debug" title="Permalink to this definition">¶</a> </dt>
<dd>Parser debug mode. If greater than 0, turn on parser debugging output (for expert only, depending
on compilation options).
Incremented by the <a class="reference internal" href="../using/cmdline.html#cmdoption-d"><code class="xref std std-option docutils literal notranslate">-d</code></a> command line option. Set to the
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONDEBUG"><code class="xref std std-envvar docutils literal notranslate">PYTHONDEBUG</code></a> environment variable value.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.pathconfig_warnings">
int pathconfig_warnings<a class="headerlink" href="#c.PyConfig.pathconfig_warnings" title="Permalink to this definition">¶</a> </dt>
<dd>On Unix, if non-zero, calculating the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> can log warnings into <code class="docutils literal notranslate">stderr</code>. If equals to 0,
suppress these warnings.
It has no effect on Windows.
Default: <code class="docutils literal notranslate">1</code> in Python mode, <code class="docutils literal notranslate">0</code> in isolated mode.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> input.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.prefix">
wchar_t *prefix<a class="headerlink" href="#c.PyConfig.prefix" title="Permalink to this definition">¶</a> </dt>
<dd>The site-specific directory prefix where the platform independent Python
files are installed: <a class="reference internal" href="../library/sys.html#sys.prefix" title="sys.prefix"><code class="xref py py-data docutils literal notranslate">sys.prefix</code></a>.
Default: <code class="docutils literal notranslate">NULL</code>.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> output.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.program_name">
wchar_t *program_name<a class="headerlink" href="#c.PyConfig.program_name" title="Permalink to this definition">¶</a> </dt>
<dd>Program name used to initialize <a class="reference internal" href="#c.PyConfig.executable" title="PyConfig.executable"><code class="xref c c-member docutils literal notranslate">executable</code></a> and in
early error messages during Python initialization.
<ul class="simple">
<li>If <code class="xref py py-func docutils literal notranslate">Py_SetProgramName()</code> has been called, use its argument.</li>
<li>On macOS, use <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONEXECUTABLE"><code class="xref std std-envvar docutils literal notranslate">PYTHONEXECUTABLE</code></a> environment variable if set.</li>
<li>If the <code class="docutils literal notranslate">WITH_NEXT_FRAMEWORK</code> macro is defined, use
<code class="xref std std-envvar docutils literal notranslate">__PYVENV_LAUNCHER__</code> environment variable if set.</li>
<li>Use <code class="docutils literal notranslate">argv[0]</code> of <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a> if available and
non-empty.</li>
<li>Otherwise, use <code class="docutils literal notranslate">L&quot;python&quot;</code> on Windows, or <code class="docutils literal notranslate">L&quot;python3&quot;</code> on other
platforms.</li>
</ul>
Default: <code class="docutils literal notranslate">NULL</code>.
Part of the <a class="reference internal" href="#init-path-config">Python Path Configuration</a> input.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.pycache_prefix">
wchar_t *pycache_prefix<a class="headerlink" href="#c.PyConfig.pycache_prefix" title="Permalink to this definition">¶</a> </dt>
<dd>Directory where cached <code class="docutils literal notranslate">.pyc</code> files are written:
<a class="reference internal" href="../library/sys.html#sys.pycache_prefix" title="sys.pycache_prefix"><code class="xref py py-data docutils literal notranslate">sys.pycache_prefix</code></a>.
Set by the <a class="reference internal" href="../using/cmdline.html#cmdoption-X"><code class="xref std std-option docutils literal notranslate">-X pycache_prefix=PATH</code></a> command line option and
the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONPYCACHEPREFIX"><code class="xref std std-envvar docutils literal notranslate">PYTHONPYCACHEPREFIX</code></a> environment variable.
If <code class="docutils literal notranslate">NULL</code>, <a class="reference internal" href="../library/sys.html#sys.pycache_prefix" title="sys.pycache_prefix"><code class="xref py py-data docutils literal notranslate">sys.pycache_prefix</code></a> is set to <code class="docutils literal notranslate">None</code>.
Default: <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.quiet">
int quiet<a class="headerlink" href="#c.PyConfig.quiet" title="Permalink to this definition">¶</a> </dt>
<dd>Quiet mode. If greater than 0, don’t display the copyright and version at
Python startup in interactive mode.
Incremented by the <a class="reference internal" href="../using/cmdline.html#cmdoption-q"><code class="xref std std-option docutils literal notranslate">-q</code></a> command line option.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.run_command">
wchar_t *run_command<a class="headerlink" href="#c.PyConfig.run_command" title="Permalink to this definition">¶</a> </dt>
<dd>Value of the <a class="reference internal" href="../using/cmdline.html#cmdoption-c"><code class="xref std std-option docutils literal notranslate">-c</code></a> command line option.
Used by <a class="reference internal" href="#c.Py_RunMain" title="Py_RunMain"><code class="xref c c-func docutils literal notranslate">Py_RunMain()</code></a>.
Default: <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.run_filename">
wchar_t *run_filename<a class="headerlink" href="#c.PyConfig.run_filename" title="Permalink to this definition">¶</a> </dt>
<dd>Filename passed on the command line: trailing command line argument
without <a class="reference internal" href="../using/cmdline.html#cmdoption-c"><code class="xref std std-option docutils literal notranslate">-c</code></a> or <a class="reference internal" href="../using/cmdline.html#cmdoption-m"><code class="xref std std-option docutils literal notranslate">-m</code></a>.
For example, it is set to <code class="docutils literal notranslate">script.py</code> by the <code class="docutils literal notranslate">python3 script.py arg</code>
command.
Used by <a class="reference internal" href="#c.Py_RunMain" title="Py_RunMain"><code class="xref c c-func docutils literal notranslate">Py_RunMain()</code></a>.
Default: <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.run_module">
wchar_t *run_module<a class="headerlink" href="#c.PyConfig.run_module" title="Permalink to this definition">¶</a> </dt>
<dd>Value of the <a class="reference internal" href="../using/cmdline.html#cmdoption-m"><code class="xref std std-option docutils literal notranslate">-m</code></a> command line option.
Used by <a class="reference internal" href="#c.Py_RunMain" title="Py_RunMain"><code class="xref c c-func docutils literal notranslate">Py_RunMain()</code></a>.
Default: <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.show_ref_count">
int show_ref_count<a class="headerlink" href="#c.PyConfig.show_ref_count" title="Permalink to this definition">¶</a> </dt>
<dd>Show total reference count at exit?
Set to 1 by <a class="reference internal" href="../using/cmdline.html#cmdoption-X"><code class="xref std std-option docutils literal notranslate">-X showrefcount</code></a> command line option.
Need a <a class="reference internal" href="../using/configure.html#debug-build">debug build of Python</a> (the <code class="docutils literal notranslate">Py_REF_DEBUG</code>
macro must be defined).
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.site_import">
int site_import<a class="headerlink" href="#c.PyConfig.site_import" title="Permalink to this definition">¶</a> </dt>
<dd>Import the <a class="reference internal" href="../library/site.html#module-site" title="site: Module responsible for site-specific configuration."><code class="xref py py-mod docutils literal notranslate">site</code></a> module at startup?
If equal to zero, disable the import of the module site and the
site-dependent manipulations of <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a> that it entails.
Also disable these manipulations if the <a class="reference internal" href="../library/site.html#module-site" title="site: Module responsible for site-specific configuration."><code class="xref py py-mod docutils literal notranslate">site</code></a> module is explicitly
imported later (call <a class="reference internal" href="../library/site.html#site.main" title="site.main"><code class="xref py py-func docutils literal notranslate">site.main()</code></a> if you want them to be triggered).
Set to <code class="docutils literal notranslate">0</code> by the <a class="reference internal" href="../using/cmdline.html#cmdoption-S"><code class="xref std std-option docutils literal notranslate">-S</code></a> command line option.
<code class="xref py py-data docutils literal notranslate">sys.flags.no_site</code> is set to the inverted value of
<a class="reference internal" href="#c.PyConfig.site_import" title="PyConfig.site_import"><code class="xref c c-member docutils literal notranslate">site_import</code></a>.
Default: <code class="docutils literal notranslate">1</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.skip_source_first_line">
int skip_source_first_line<a class="headerlink" href="#c.PyConfig.skip_source_first_line" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, skip the first line of the <a class="reference internal" href="#c.PyConfig.run_filename" title="PyConfig.run_filename"><code class="xref c c-member docutils literal notranslate">PyConfig.run_filename</code></a>
source.
It allows the usage of non-Unix forms of <code class="docutils literal notranslate">#!cmd</code>. This is intended for
a DOS specific hack only.
Set to <code class="docutils literal notranslate">1</code> by the <a class="reference internal" href="../using/cmdline.html#cmdoption-x"><code class="xref std std-option docutils literal notranslate">-x</code></a> command line option.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.stdio_encoding">
wchar_t *stdio_encoding<a class="headerlink" href="#c.PyConfig.stdio_encoding" title="Permalink to this definition">¶</a> </dt>
<dd></dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.stdio_errors">
wchar_t *stdio_errors<a class="headerlink" href="#c.PyConfig.stdio_errors" title="Permalink to this definition">¶</a> </dt>
<dd>Encoding and encoding errors of <a class="reference internal" href="../library/sys.html#sys.stdin" title="sys.stdin"><code class="xref py py-data docutils literal notranslate">sys.stdin</code></a>, <a class="reference internal" href="../library/sys.html#sys.stdout" title="sys.stdout"><code class="xref py py-data docutils literal notranslate">sys.stdout</code></a> and
<a class="reference internal" href="../library/sys.html#sys.stderr" title="sys.stderr"><code class="xref py py-data docutils literal notranslate">sys.stderr</code></a> (but <a class="reference internal" href="../library/sys.html#sys.stderr" title="sys.stderr"><code class="xref py py-data docutils literal notranslate">sys.stderr</code></a> always uses
<code class="docutils literal notranslate">&quot;backslashreplace&quot;</code> error handler).
If <a class="reference internal" href="init.html#c.Py_SetStandardStreamEncoding" title="Py_SetStandardStreamEncoding"><code class="xref c c-func docutils literal notranslate">Py_SetStandardStreamEncoding()</code></a> has been called, use its
error and errors arguments if they are not <code class="docutils literal notranslate">NULL</code>.
Use the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONIOENCODING"><code class="xref std std-envvar docutils literal notranslate">PYTHONIOENCODING</code></a> environment variable if it is
non-empty.
Default encoding:
<ul class="simple">
<li><code class="docutils literal notranslate">&quot;UTF-8&quot;</code> if <a class="reference internal" href="#c.PyPreConfig.utf8_mode" title="PyPreConfig.utf8_mode"><code class="xref c c-member docutils literal notranslate">PyPreConfig.utf8_mode</code></a> is non-zero.</li>
<li>Otherwise, use the <a class="reference internal" href="../glossary.html#term-locale-encoding">locale encoding</a>.</li>
</ul>
Default error handler:
<ul class="simple">
<li>On Windows: use <code class="docutils literal notranslate">&quot;surrogateescape&quot;</code>.</li>
<li><code class="docutils literal notranslate">&quot;surrogateescape&quot;</code> if <a class="reference internal" href="#c.PyPreConfig.utf8_mode" title="PyPreConfig.utf8_mode"><code class="xref c c-member docutils literal notranslate">PyPreConfig.utf8_mode</code></a> is non-zero,
or if the LC_CTYPE locale is “C” or “POSIX”.</li>
<li><code class="docutils literal notranslate">&quot;strict&quot;</code> otherwise.</li>
</ul>
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.tracemalloc">
int tracemalloc<a class="headerlink" href="#c.PyConfig.tracemalloc" title="Permalink to this definition">¶</a> </dt>
<dd>Enable tracemalloc?
If non-zero, call <a class="reference internal" href="../library/tracemalloc.html#tracemalloc.start" title="tracemalloc.start"><code class="xref py py-func docutils literal notranslate">tracemalloc.start()</code></a> at startup.
Set by <a class="reference internal" href="../using/cmdline.html#cmdoption-X"><code class="xref std std-option docutils literal notranslate">-X tracemalloc=N</code></a> command line option and by the
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONTRACEMALLOC"><code class="xref std std-envvar docutils literal notranslate">PYTHONTRACEMALLOC</code></a> environment variable.
Default: <code class="docutils literal notranslate">-1</code> in Python mode, <code class="docutils literal notranslate">0</code> in isolated mode.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.use_environment">
int use_environment<a class="headerlink" href="#c.PyConfig.use_environment" title="Permalink to this definition">¶</a> </dt>
<dd>Use <a class="reference internal" href="../using/cmdline.html#using-on-envvars">environment variables</a>?
If equals to zero, ignore the <a class="reference internal" href="../using/cmdline.html#using-on-envvars">environment variables</a>.
Default: <code class="docutils literal notranslate">1</code> in Python config and <code class="docutils literal notranslate">0</code> in isolated config.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.user_site_directory">
int user_site_directory<a class="headerlink" href="#c.PyConfig.user_site_directory" title="Permalink to this definition">¶</a> </dt>
<dd>If non-zero, add the user site directory to <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>.
Set to <code class="docutils literal notranslate">0</code> by the <a class="reference internal" href="../using/cmdline.html#cmdoption-s"><code class="xref std std-option docutils literal notranslate">-s</code></a> and <a class="reference internal" href="../using/cmdline.html#cmdoption-I"><code class="xref std std-option docutils literal notranslate">-I</code></a> command line options.
Set to <code class="docutils literal notranslate">0</code> by the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONNOUSERSITE"><code class="xref std std-envvar docutils literal notranslate">PYTHONNOUSERSITE</code></a> environment variable.
Default: <code class="docutils literal notranslate">1</code> in Python mode, <code class="docutils literal notranslate">0</code> in isolated mode.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.verbose">
int verbose<a class="headerlink" href="#c.PyConfig.verbose" title="Permalink to this definition">¶</a> </dt>
<dd>Verbose mode. If greater than 0, print a message each time a module is
imported, showing the place (filename or built-in module) from which
it is loaded.
If greater or equal to 2, print a message for each file that is checked
for when searching for a module. Also provides information on module
cleanup at exit.
Incremented by the <a class="reference internal" href="../using/cmdline.html#cmdoption-1"><code class="xref std std-option docutils literal notranslate">-v</code></a> command line option.
Set to the <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONVERBOSE"><code class="xref std std-envvar docutils literal notranslate">PYTHONVERBOSE</code></a> environment variable value.
Default: <code class="docutils literal notranslate">0</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.warnoptions">
<a class="reference internal" href="#c.PyWideStringList" title="PyWideStringList">PyWideStringList</a> warnoptions<a class="headerlink" href="#c.PyConfig.warnoptions" title="Permalink to this definition">¶</a> </dt>
<dd>Options of the <a class="reference internal" href="../library/warnings.html#module-warnings" title="warnings: Issue warning messages and control their disposition."><code class="xref py py-mod docutils literal notranslate">warnings</code></a> module to build warnings filters, lowest
to highest priority: <a class="reference internal" href="../library/sys.html#sys.warnoptions" title="sys.warnoptions"><code class="xref py py-data docutils literal notranslate">sys.warnoptions</code></a>.
The <a class="reference internal" href="../library/warnings.html#module-warnings" title="warnings: Issue warning messages and control their disposition."><code class="xref py py-mod docutils literal notranslate">warnings</code></a> module adds <a class="reference internal" href="../library/sys.html#sys.warnoptions" title="sys.warnoptions"><code class="xref py py-data docutils literal notranslate">sys.warnoptions</code></a> in the reverse
order: the last <a class="reference internal" href="#c.PyConfig.warnoptions" title="PyConfig.warnoptions"><code class="xref c c-member docutils literal notranslate">PyConfig.warnoptions</code></a> item becomes the first
item of <code class="xref py py-data docutils literal notranslate">warnings.filters</code> which is checked first (highest
priority).
The <a class="reference internal" href="../using/cmdline.html#cmdoption-W"><code class="xref std std-option docutils literal notranslate">-W</code></a> command line options adds its value to
<a class="reference internal" href="#c.PyConfig.warnoptions" title="PyConfig.warnoptions"><code class="xref c c-member docutils literal notranslate">warnoptions</code></a>, it can be used multiple times.
The <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONWARNINGS"><code class="xref std std-envvar docutils literal notranslate">PYTHONWARNINGS</code></a> environment variable can also be used to add
warning options. Multiple options can be specified, separated by commas
(<code class="docutils literal notranslate">,</code>).
Default: empty list.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.write_bytecode">
int write_bytecode<a class="headerlink" href="#c.PyConfig.write_bytecode" title="Permalink to this definition">¶</a> </dt>
<dd>If equal to 0, Python won’t try to write <code class="docutils literal notranslate">.pyc</code> files on the import of
source modules.
Set to <code class="docutils literal notranslate">0</code> by the <a class="reference internal" href="../using/cmdline.html#cmdoption-B"><code class="xref std std-option docutils literal notranslate">-B</code></a> command line option and the
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONDONTWRITEBYTECODE"><code class="xref std std-envvar docutils literal notranslate">PYTHONDONTWRITEBYTECODE</code></a> environment variable.
<a class="reference internal" href="../library/sys.html#sys.dont_write_bytecode" title="sys.dont_write_bytecode"><code class="xref py py-data docutils literal notranslate">sys.dont_write_bytecode</code></a> is initialized to the inverted value of
<a class="reference internal" href="#c.PyConfig.write_bytecode" title="PyConfig.write_bytecode"><code class="xref c c-member docutils literal notranslate">write_bytecode</code></a>.
Default: <code class="docutils literal notranslate">1</code>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyConfig.xoptions">
<a class="reference internal" href="#c.PyWideStringList" title="PyWideStringList">PyWideStringList</a> xoptions<a class="headerlink" href="#c.PyConfig.xoptions" title="Permalink to this definition">¶</a> </dt>
<dd>Values of the <a class="reference internal" href="../using/cmdline.html#cmdoption-X"><code class="xref std std-option docutils literal notranslate">-X</code></a> command line options: <a class="reference internal" href="../library/sys.html#sys._xoptions" title="sys._xoptions"><code class="xref py py-data docutils literal notranslate">sys._xoptions</code></a>.
Default: empty list.
</dd></dl>

</dd></dl>

If <a class="reference internal" href="#c.PyConfig.parse_argv" title="PyConfig.parse_argv"><code class="xref c c-member docutils literal notranslate">parse_argv</code></a> is non-zero, <a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a>
arguments are parsed the same way the regular Python parses <a class="reference internal" href="../using/cmdline.html#using-on-cmdline">command line
arguments</a>, and Python arguments are stripped from
<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">argv</code></a>.
The <a class="reference internal" href="#c.PyConfig.xoptions" title="PyConfig.xoptions"><code class="xref c c-member docutils literal notranslate">xoptions</code></a> options are parsed to set other options: see
the <a class="reference internal" href="../using/cmdline.html#cmdoption-X"><code class="xref std std-option docutils literal notranslate">-X</code></a> command line option.
<div class="versionchanged">
Changed in version 3.9: The <code class="docutils literal notranslate">show_alloc_count</code> field has been removed.
</div>
</section>
<section id="initialization-with-pyconfig">
<h2>Initialization with PyConfig<a class="headerlink" href="#initialization-with-pyconfig" title="Permalink to this headline">¶</a></h2>
Function to initialize Python:
<dl class="c function">
<dt class="sig sig-object c" id="c.Py_InitializeFromConfig">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> Py_InitializeFromConfig(const <a class="reference internal" href="#c.PyConfig" title="PyConfig">PyConfig</a> *config)<a class="headerlink" href="#c.Py_InitializeFromConfig" title="Permalink to this definition">¶</a> </dt>
<dd>Initialize Python from config configuration.
</dd></dl>

/* Set the program name. Implicitly preinitialize Python. */
 status = PyConfig_SetString(&amp;config, &amp;config.program_name,
 L&quot;/path/to/my_program&quot;);
 if (PyStatus_Exception(status)) {
 goto exception;
 }

/* Set the program name before reading the configuration
 (decode byte string from the locale encoding).

Implicitly preinitialize Python. */
 status = PyConfig_SetBytesString(&amp;config, &amp;config.program_name,
 program_name);
 if (PyStatus_Exception(status)) {
 goto done;
 }

/* Read all configuration at once */
 status = PyConfig_Read(&amp;config);
 if (PyStatus_Exception(status)) {
 goto done;
 }

/* Append our custom search path to sys.path */
 status = PyWideStringList_Append(&amp;config.module_search_paths,
 L&quot;/path/to/more/modules&quot;);
 if (PyStatus_Exception(status)) {
 goto done;
 }

/* Override executable computed by PyConfig_Read() */
 status = PyConfig_SetString(&amp;config, &amp;config.executable,
 L&quot;/path/to/my_executable&quot;);
 if (PyStatus_Exception(status)) {
 goto done;
 }

done:
 PyConfig_Clear(&amp;config);
 return status;
}
</pre></div>
</div>
</section>
<section id="isolated-configuration">
<h2>Isolated Configuration<a class="headerlink" href="#isolated-configuration" title="Permalink to this headline">¶</a></h2>
<code class="xref c c-func docutils literal notranslate">PyPreConfig_InitIsolatedConfig()</code> and
<code class="xref c c-func docutils literal notranslate">PyConfig_InitIsolatedConfig()</code> functions create a configuration to
isolate Python from the system. For example, to embed Python into an
application.
This configuration ignores global configuration variables, environment
variables, command line arguments (<a class="reference internal" href="#c.PyConfig.argv" title="PyConfig.argv"><code class="xref c c-member docutils literal notranslate">PyConfig.argv</code></a> is not parsed)
and user site directory. The C standard streams (ex: <code class="docutils literal notranslate">stdout</code>) and the
LC_CTYPE locale are left unchanged. Signal handlers are not installed.
Configuration files are still used with this configuration. Set the
<a class="reference internal" href="#init-path-config">Python Path Configuration</a> (“output fields”) to ignore these
configuration files and avoid the function computing the default path
configuration.
</section>
<section id="python-configuration">
<h2>Python Configuration<a class="headerlink" href="#python-configuration" title="Permalink to this headline">¶</a></h2>
<code class="xref c c-func docutils literal notranslate">PyPreConfig_InitPythonConfig()</code> and <code class="xref c c-func docutils literal notranslate">PyConfig_InitPythonConfig()</code>
functions create a configuration to build a customized Python which behaves as
the regular Python.
Environments variables and command line arguments are used to configure
Python, whereas global configuration variables are ignored.
This function enables C locale coercion (<a class="pep reference external" href="https://www.python.org/dev/peps/pep-0538">PEP 538</a>)
and <a class="reference internal" href="../library/os.html#utf8-mode">Python UTF-8 Mode</a>
(<a class="pep reference external" href="https://www.python.org/dev/peps/pep-0540">PEP 540</a>) depending on the LC_CTYPE locale, <a class="reference internal" href="../using/cmdline.html#envvar-PYTHONUTF8"><code class="xref std std-envvar docutils literal notranslate">PYTHONUTF8</code></a> and
<a class="reference internal" href="../using/cmdline.html#envvar-PYTHONCOERCECLOCALE"><code class="xref std std-envvar docutils literal notranslate">PYTHONCOERCECLOCALE</code></a> environment variables.
</section>
<section id="python-path-configuration">
<h2>Python Path Configuration<a class="headerlink" href="#python-path-configuration" title="Permalink to this headline">¶</a></h2>
<a class="reference internal" href="#c.PyConfig" title="PyConfig"><code class="xref c c-type docutils literal notranslate">PyConfig</code></a> contains multiple fields for the path configuration:
<ul class="simple">
<li>Path configuration inputs:
<ul>
<li><a class="reference internal" href="#c.PyConfig.home" title="PyConfig.home"><code class="xref c c-member docutils literal notranslate">PyConfig.home</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.platlibdir" title="PyConfig.platlibdir"><code class="xref c c-member docutils literal notranslate">PyConfig.platlibdir</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.pathconfig_warnings" title="PyConfig.pathconfig_warnings"><code class="xref c c-member docutils literal notranslate">PyConfig.pathconfig_warnings</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.program_name" title="PyConfig.program_name"><code class="xref c c-member docutils literal notranslate">PyConfig.program_name</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.pythonpath_env" title="PyConfig.pythonpath_env"><code class="xref c c-member docutils literal notranslate">PyConfig.pythonpath_env</code></a></li>
<li>current working directory: to get absolute paths</li>
<li><code class="docutils literal notranslate">PATH</code> environment variable to get the program full path
(from <a class="reference internal" href="#c.PyConfig.program_name" title="PyConfig.program_name"><code class="xref c c-member docutils literal notranslate">PyConfig.program_name</code></a>)</li>
<li><code class="docutils literal notranslate">__PYVENV_LAUNCHER__</code> environment variable</li>
<li>(Windows only) Application paths in the registry under
“SoftwarePythonPythonCoreX.YPythonPath” of HKEY_CURRENT_USER and
HKEY_LOCAL_MACHINE (where X.Y is the Python version).</li>
</ul>
</li>
<li>Path configuration output fields:
<ul>
<li><a class="reference internal" href="#c.PyConfig.base_exec_prefix" title="PyConfig.base_exec_prefix"><code class="xref c c-member docutils literal notranslate">PyConfig.base_exec_prefix</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.base_executable" title="PyConfig.base_executable"><code class="xref c c-member docutils literal notranslate">PyConfig.base_executable</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.base_prefix" title="PyConfig.base_prefix"><code class="xref c c-member docutils literal notranslate">PyConfig.base_prefix</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.exec_prefix" title="PyConfig.exec_prefix"><code class="xref c c-member docutils literal notranslate">PyConfig.exec_prefix</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.executable" title="PyConfig.executable"><code class="xref c c-member docutils literal notranslate">PyConfig.executable</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.module_search_paths_set" title="PyConfig.module_search_paths_set"><code class="xref c c-member docutils literal notranslate">PyConfig.module_search_paths_set</code></a>,
<a class="reference internal" href="#c.PyConfig.module_search_paths" title="PyConfig.module_search_paths"><code class="xref c c-member docutils literal notranslate">PyConfig.module_search_paths</code></a></li>
<li><a class="reference internal" href="#c.PyConfig.prefix" title="PyConfig.prefix"><code class="xref c c-member docutils literal notranslate">PyConfig.prefix</code></a></li>
</ul>
</li>
</ul>
If at least one “output field” is not set, Python calculates the path
configuration to fill unset fields. If
<a class="reference internal" href="#c.PyConfig.module_search_paths_set" title="PyConfig.module_search_paths_set"><code class="xref c c-member docutils literal notranslate">module_search_paths_set</code></a> is equal to 0,
<a class="reference internal" href="#c.PyConfig.module_search_paths" title="PyConfig.module_search_paths"><code class="xref c c-member docutils literal notranslate">module_search_paths</code></a> is overridden and
<a class="reference internal" href="#c.PyConfig.module_search_paths_set" title="PyConfig.module_search_paths_set"><code class="xref c c-member docutils literal notranslate">module_search_paths_set</code></a> is set to 1.
It is possible to completely ignore the function calculating the default
path configuration by setting explicitly all path configuration output
fields listed above. A string is considered as set even if it is non-empty.
<code class="docutils literal notranslate">module_search_paths</code> is considered as set if
<code class="docutils literal notranslate">module_search_paths_set</code> is set to 1. In this case, path
configuration input fields are ignored as well.
Set <a class="reference internal" href="#c.PyConfig.pathconfig_warnings" title="PyConfig.pathconfig_warnings"><code class="xref c c-member docutils literal notranslate">pathconfig_warnings</code></a> to 0 to suppress warnings when
calculating the path configuration (Unix only, Windows does not log any warning).
If <a class="reference internal" href="#c.PyConfig.base_prefix" title="PyConfig.base_prefix"><code class="xref c c-member docutils literal notranslate">base_prefix</code></a> or <a class="reference internal" href="#c.PyConfig.base_exec_prefix" title="PyConfig.base_exec_prefix"><code class="xref c c-member docutils literal notranslate">base_exec_prefix</code></a>
fields are not set, they inherit their value from <a class="reference internal" href="#c.PyConfig.prefix" title="PyConfig.prefix"><code class="xref c c-member docutils literal notranslate">prefix</code></a>
and <a class="reference internal" href="#c.PyConfig.exec_prefix" title="PyConfig.exec_prefix"><code class="xref c c-member docutils literal notranslate">exec_prefix</code></a> respectively.
<a class="reference internal" href="#c.Py_RunMain" title="Py_RunMain"><code class="xref c c-func docutils literal notranslate">Py_RunMain()</code></a> and <a class="reference internal" href="veryhigh.html#c.Py_Main" title="Py_Main"><code class="xref c c-func docutils literal notranslate">Py_Main()</code></a> modify <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>:
<ul class="simple">
<li>If <a class="reference internal" href="#c.PyConfig.run_filename" title="PyConfig.run_filename"><code class="xref c c-member docutils literal notranslate">run_filename</code></a> is set and is a directory which contains a
<code class="docutils literal notranslate">__main__.py</code> script, prepend <a class="reference internal" href="#c.PyConfig.run_filename" title="PyConfig.run_filename"><code class="xref c c-member docutils literal notranslate">run_filename</code></a> to
<a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>.</li>
<li>If <a class="reference internal" href="#c.PyConfig.isolated" title="PyConfig.isolated"><code class="xref c c-member docutils literal notranslate">isolated</code></a> is zero:
<ul>
<li>If <a class="reference internal" href="#c.PyConfig.run_module" title="PyConfig.run_module"><code class="xref c c-member docutils literal notranslate">run_module</code></a> is set, prepend the current directory
to <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>. Do nothing if the current directory cannot be read.</li>
<li>If <a class="reference internal" href="#c.PyConfig.run_filename" title="PyConfig.run_filename"><code class="xref c c-member docutils literal notranslate">run_filename</code></a> is set, prepend the directory of the
filename to <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>.</li>
<li>Otherwise, prepend an empty string to <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>.</li>
</ul>
</li>
</ul>
If <a class="reference internal" href="#c.PyConfig.site_import" title="PyConfig.site_import"><code class="xref c c-member docutils literal notranslate">site_import</code></a> is non-zero, <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a> can be
modified by the <a class="reference internal" href="../library/site.html#module-site" title="site: Module responsible for site-specific configuration."><code class="xref py py-mod docutils literal notranslate">site</code></a> module. If
<a class="reference internal" href="#c.PyConfig.user_site_directory" title="PyConfig.user_site_directory"><code class="xref c c-member docutils literal notranslate">user_site_directory</code></a> is non-zero and the user’s
site-package directory exists, the <a class="reference internal" href="../library/site.html#module-site" title="site: Module responsible for site-specific configuration."><code class="xref py py-mod docutils literal notranslate">site</code></a> module appends the user’s
site-package directory to <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>.
The following configuration files are used by the path configuration:
<ul class="simple">
<li><code class="docutils literal notranslate">pyvenv.cfg</code></li>
<li><code class="docutils literal notranslate">python._pth</code> (Windows only)</li>
<li><code class="docutils literal notranslate">pybuilddir.txt</code> (Unix only)</li>
</ul>
The <code class="docutils literal notranslate">__PYVENV_LAUNCHER__</code> environment variable is used to set
<a class="reference internal" href="#c.PyConfig.base_executable" title="PyConfig.base_executable"><code class="xref c c-member docutils literal notranslate">PyConfig.base_executable</code></a>
</section>
<section id="py-runmain">
<h2>Py_RunMain()<a class="headerlink" href="#py-runmain" title="Permalink to this headline">¶</a></h2>
<dl class="c function">
<dt class="sig sig-object c" id="c.Py_RunMain">
int Py_RunMain(void)<a class="headerlink" href="#c.Py_RunMain" title="Permalink to this definition">¶</a> </dt>
<dd>Execute the command (<a class="reference internal" href="#c.PyConfig.run_command" title="PyConfig.run_command"><code class="xref c c-member docutils literal notranslate">PyConfig.run_command</code></a>), the script
(<a class="reference internal" href="#c.PyConfig.run_filename" title="PyConfig.run_filename"><code class="xref c c-member docutils literal notranslate">PyConfig.run_filename</code></a>) or the module
(<a class="reference internal" href="#c.PyConfig.run_module" title="PyConfig.run_module"><code class="xref c c-member docutils literal notranslate">PyConfig.run_module</code></a>) specified on the command line or in the
configuration.
By default and when if <a class="reference internal" href="../using/cmdline.html#cmdoption-i"><code class="xref std std-option docutils literal notranslate">-i</code></a> option is used, run the REPL.
Finally, finalizes Python and returns an exit status that can be passed to
the <code class="docutils literal notranslate">exit()</code> function.
</dd></dl>

See <a class="reference internal" href="#init-python-config">Python Configuration</a> for an example of
customized Python always running in isolated mode using
<a class="reference internal" href="#c.Py_RunMain" title="Py_RunMain"><code class="xref c c-func docutils literal notranslate">Py_RunMain()</code></a>.
</section>
<section id="py-getargcargv">
<h2>Py_GetArgcArgv()<a class="headerlink" href="#py-getargcargv" title="Permalink to this headline">¶</a></h2>
<dl class="c function">
<dt class="sig sig-object c" id="c.Py_GetArgcArgv">
void Py_GetArgcArgv(int *argc, wchar_t ***argv)<a class="headerlink" href="#c.Py_GetArgcArgv" title="Permalink to this definition">¶</a> </dt>
<dd>Get the original command line arguments, before Python modified them.
See also <a class="reference internal" href="#c.PyConfig.orig_argv" title="PyConfig.orig_argv"><code class="xref c c-member docutils literal notranslate">PyConfig.orig_argv</code></a> member.
</dd></dl>

</section>
<section id="multi-phase-initialization-private-provisional-api">
<h2>Multi-Phase Initialization Private Provisional API<a class="headerlink" href="#multi-phase-initialization-private-provisional-api" title="Permalink to this headline">¶</a></h2>
This section is a private provisional API introducing multi-phase
initialization, the core feature of <a class="pep reference external" href="https://www.python.org/dev/peps/pep-0432">PEP 432</a>:
<ul class="simple">
<li>“Core” initialization phase, “bare minimum Python”:
<ul>
<li>Builtin types;</li>
<li>Builtin exceptions;</li>
<li>Builtin and frozen modules;</li>
<li>The <a class="reference internal" href="../library/sys.html#module-sys" title="sys: Access system-specific parameters and functions."><code class="xref py py-mod docutils literal notranslate">sys</code></a> module is only partially initialized
(ex: <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a> doesn’t exist yet).</li>
</ul>
</li>
<li>“Main” initialization phase, Python is fully initialized:
<ul>
<li>Install and configure <a class="reference internal" href="../library/importlib.html#module-importlib" title="importlib: The implementation of the import machinery."><code class="xref py py-mod docutils literal notranslate">importlib</code></a>;</li>
<li>Apply the <a class="reference internal" href="#init-path-config">Path Configuration</a>;</li>
<li>Install signal handlers;</li>
<li>Finish <a class="reference internal" href="../library/sys.html#module-sys" title="sys: Access system-specific parameters and functions."><code class="xref py py-mod docutils literal notranslate">sys</code></a> module initialization (ex: create <a class="reference internal" href="../library/sys.html#sys.stdout" title="sys.stdout"><code class="xref py py-data docutils literal notranslate">sys.stdout</code></a>
and <a class="reference internal" href="../library/sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate">sys.path</code></a>);</li>
<li>Enable optional features like <a class="reference internal" href="../library/faulthandler.html#module-faulthandler" title="faulthandler: Dump the Python traceback."><code class="xref py py-mod docutils literal notranslate">faulthandler</code></a> and <a class="reference internal" href="../library/tracemalloc.html#module-tracemalloc" title="tracemalloc: Trace memory allocations."><code class="xref py py-mod docutils literal notranslate">tracemalloc</code></a>;</li>
<li>Import the <a class="reference internal" href="../library/site.html#module-site" title="site: Module responsible for site-specific configuration."><code class="xref py py-mod docutils literal notranslate">site</code></a> module;</li>
<li>etc.</li>
</ul>
</li>
</ul>
Private provisional API:
<ul class="simple">
<li><code class="xref c c-member docutils literal notranslate">PyConfig._init_main</code>: if set to 0,
<a class="reference internal" href="#c.Py_InitializeFromConfig" title="Py_InitializeFromConfig"><code class="xref c c-func docutils literal notranslate">Py_InitializeFromConfig()</code></a> stops at the “Core” initialization phase.</li>
<li><code class="xref c c-member docutils literal notranslate">PyConfig._isolated_interpreter</code>: if non-zero,
disallow threads, subprocesses and fork.</li>
</ul>
<dl class="c function">
<dt class="sig sig-object c" id="c._Py_InitializeMain">
<a class="reference internal" href="#c.PyStatus" title="PyStatus">PyStatus</a> _Py_InitializeMain(void)<a class="headerlink" href="#c._Py_InitializeMain" title="Permalink to this definition">¶</a> </dt>
<dd>Move to the “Main” initialization phase, finish the Python initialization.
</dd></dl>

No module is imported during the “Core” phase and the <code class="docutils literal notranslate">importlib</code> module is
not configured: the <a class="reference internal" href="#init-path-config">Path Configuration</a> is only
applied during the “Main” phase. It may allow to customize Python in Python to
override or tune the <a class="reference internal" href="#init-path-config">Path Configuration</a>, maybe
install a custom <a class="reference internal" href="../library/sys.html#sys.meta_path" title="sys.meta_path"><code class="xref py py-data docutils literal notranslate">sys.meta_path</code></a> importer or an import hook, etc.
It may become possible to calculatin the <a class="reference internal" href="#init-path-config">Path Configuration</a> in Python, after the Core phase and before the Main phase,
which is one of the <a class="pep reference external" href="https://www.python.org/dev/peps/pep-0432">PEP 432</a> motivation.
The “Core” phase is not properly defined: what should be and what should
not be available at this phase is not specified yet. The API is marked
as private and provisional: the API can be modified or even be removed
anytime until a proper public API is designed.
Example running Python code between “Core” and “Main” initialization
phases:
<div class="highlight-c notranslate"><div class="highlight"><pre>void init_python(void)
{
 PyStatus status;

PyConfig config;
 PyConfig_InitPythonConfig(&amp;config);
 config._init_main = 0;

/* ... customize &#39;config&#39; configuration ... */

status = Py_InitializeFromConfig(&amp;config);
 PyConfig_Clear(&amp;config);
 if (PyStatus_Exception(status)) {
 Py_ExitStatusException(status);
 }

/* Use sys.stderr because sys.stdout is only created
 by _Py_InitializeMain() */
 int res = PyRun_SimpleString(
 &quot;import sys; &quot;
 &quot;print(&#39;Run Python code before _Py_InitializeMain&#39;, &quot;
 &quot;file=sys.stderr)&quot;);
 if (res &lt; 0) {
 exit(1);
 }

/* ... put more configuration code here ... */

status = _Py_InitializeMain();
 if (PyStatus_Exception(status)) {
 Py_ExitStatusException(status);
 }
}
</pre></div>
</div>
</section>
</section>

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 <h3><a href="../contents.html">Table of Contents</a></h3>
 <ul>
<li><a class="reference internal" href="#">Python Initialization Configuration</a><ul>
<li><a class="reference internal" href="#example">Example</a></li>
<li><a class="reference internal" href="#pywidestringlist">PyWideStringList</a></li>
<li><a class="reference internal" href="#pystatus">PyStatus</a></li>
<li><a class="reference internal" href="#pypreconfig">PyPreConfig</a></li>
<li><a class="reference internal" href="#preinitialize-python-with-pypreconfig">Preinitialize Python with PyPreConfig</a></li>
<li><a class="reference internal" href="#pyconfig">PyConfig</a></li>
<li><a class="reference internal" href="#initialization-with-pyconfig">Initialization with PyConfig</a></li>
<li><a class="reference internal" href="#isolated-configuration">Isolated Configuration</a></li>
<li><a class="reference internal" href="#python-configuration">Python Configuration</a></li>
<li><a class="reference internal" href="#python-path-configuration">Python Path Configuration</a></li>
<li><a class="reference internal" href="#py-runmain">Py_RunMain()</a></li>
<li><a class="reference internal" href="#py-getargcargv">Py_GetArgcArgv()</a></li>
<li><a class="reference internal" href="#multi-phase-initialization-private-provisional-api">Multi-Phase Initialization Private Provisional API</a></li>
</ul>
</li>
</ul>

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