Gecko [ fernandoquevedodop.com ]

Name	Size	Permission
2to3.html	70.96 KB	-rw-r--r--
__future__.html	20.75 KB	-rw-r--r--
__main__.html	44.87 KB	-rw-r--r--
_thread.html	30.39 KB	-rw-r--r--
abc.html	46.87 KB	-rw-r--r--
aifc.html	35.56 KB	-rw-r--r--
allos.html	34.33 KB	-rw-r--r--
archiving.html	17 KB	-rw-r--r--
argparse.html	300.89 KB	-rw-r--r--
array.html	37.28 KB	-rw-r--r--
ast.html	293.08 KB	-rw-r--r--
asynchat.html	37.41 KB	-rw-r--r--
asyncio-api-index.html	27.68 KB	-rw-r--r--
asyncio-dev.html	36.1 KB	-rw-r--r--
asyncio-eventloop.html	204.43 KB	-rw-r--r--
asyncio-exceptions.html	17.11 KB	-rw-r--r--
asyncio-future.html	38.23 KB	-rw-r--r--
asyncio-llapi-index.html	61.97 KB	-rw-r--r--
asyncio-platforms.html	21.77 KB	-rw-r--r--
asyncio-policy.html	39.56 KB	-rw-r--r--
asyncio-protocol.html	118.33 KB	-rw-r--r--
asyncio-queue.html	31.86 KB	-rw-r--r--
asyncio-stream.html	69.98 KB	-rw-r--r--
asyncio-subprocess.html	49.25 KB	-rw-r--r--
asyncio-sync.html	42.79 KB	-rw-r--r--
asyncio-task.html	109.14 KB	-rw-r--r--
asyncio.html	17.31 KB	-rw-r--r--
asyncore.html	49.36 KB	-rw-r--r--
atexit.html	22.87 KB	-rw-r--r--
audioop.html	46 KB	-rw-r--r--
audit_events.html	72.85 KB	-rw-r--r--
base64.html	48.09 KB	-rw-r--r--
bdb.html	66 KB	-rw-r--r--
binary.html	15.97 KB	-rw-r--r--
binascii.html	36.3 KB	-rw-r--r--
binhex.html	15.97 KB	-rw-r--r--
bisect.html	43.38 KB	-rw-r--r--
builtins.html	14.87 KB	-rw-r--r--
bz2.html	50.68 KB	-rw-r--r--
calendar.html	69.35 KB	-rw-r--r--
cgi.html	59.95 KB	-rw-r--r--
cgitb.html	19.96 KB	-rw-r--r--
chunk.html	22.21 KB	-rw-r--r--
cmath.html	43.89 KB	-rw-r--r--
cmd.html	50.42 KB	-rw-r--r--
code.html	35.38 KB	-rw-r--r--
codecs.html	157.96 KB	-rw-r--r--
codeop.html	18.26 KB	-rw-r--r--
collections.abc.html	79.17 KB	-rw-r--r--
collections.html	189.43 KB	-rw-r--r--
colorsys.html	17.31 KB	-rw-r--r--
compileall.html	50.68 KB	-rw-r--r--
concurrency.html	24.15 KB	-rw-r--r--
concurrent.futures.html	79.03 KB	-rw-r--r--
concurrent.html	11.56 KB	-rw-r--r--
configparser.html	159.4 KB	-rw-r--r--
constants.html	22.41 KB	-rw-r--r--
contextlib.html	117.2 KB	-rw-r--r--
contextvars.html	38.38 KB	-rw-r--r--
copy.html	17.92 KB	-rw-r--r--
copyreg.html	18.63 KB	-rw-r--r--
crypt.html	28.29 KB	-rw-r--r--
crypto.html	13.93 KB	-rw-r--r--
csv.html	82.89 KB	-rw-r--r--
ctypes.html	295.49 KB	-rw-r--r--
curses.ascii.html	32.04 KB	-rw-r--r--
curses.html	221.24 KB	-rw-r--r--
curses.panel.html	22.16 KB	-rw-r--r--
custominterp.html	11.85 KB	-rw-r--r--
dataclasses.html	113.16 KB	-rw-r--r--
datatypes.html	31.82 KB	-rw-r--r--
datetime.html	374.92 KB	-rw-r--r--
dbm.html	51.16 KB	-rw-r--r--
debug.html	17 KB	-rw-r--r--
decimal.html	270.12 KB	-rw-r--r--
development.html	32.34 KB	-rw-r--r--
devmode.html	31.72 KB	-rw-r--r--
dialog.html	43.03 KB	-rw-r--r--
difflib.html	111.99 KB	-rw-r--r--
dis.html	136.07 KB	-rw-r--r--
distribution.html	13.67 KB	-rw-r--r--
distutils.html	14.73 KB	-rw-r--r--
doctest.html	199.32 KB	-rw-r--r--
email.charset.html	31.92 KB	-rw-r--r--
email.compat32-message.html	97.74 KB	-rw-r--r--
email.contentmanager.html	37.02 KB	-rw-r--r--
email.encoders.html	18.47 KB	-rw-r--r--
email.errors.html	24.45 KB	-rw-r--r--
email.examples.html	60.49 KB	-rw-r--r--
email.generator.html	48.79 KB	-rw-r--r--
email.header.html	37.61 KB	-rw-r--r--
email.headerregistry.html	66.26 KB	-rw-r--r--
email.html	30.75 KB	-rw-r--r--
email.iterators.html	18.23 KB	-rw-r--r--
email.message.html	99.75 KB	-rw-r--r--
email.mime.html	44.89 KB	-rw-r--r--
email.parser.html	57.39 KB	-rw-r--r--
email.policy.html	84.24 KB	-rw-r--r--
email.utils.html	42.57 KB	-rw-r--r--
ensurepip.html	23.9 KB	-rw-r--r--
enum.html	151 KB	-rw-r--r--
errno.html	60.17 KB	-rw-r--r--
exceptions.html	108.44 KB	-rw-r--r--
faulthandler.html	31.5 KB	-rw-r--r--
fcntl.html	36.67 KB	-rw-r--r--
filecmp.html	32.08 KB	-rw-r--r--
fileformats.html	13.52 KB	-rw-r--r--
fileinput.html	40.37 KB	-rw-r--r--
filesys.html	16.78 KB	-rw-r--r--
fnmatch.html	21.02 KB	-rw-r--r--
fractions.html	35.29 KB	-rw-r--r--
frameworks.html	16.15 KB	-rw-r--r--
ftplib.html	71.97 KB	-rw-r--r--
functional.html	12.19 KB	-rw-r--r--
functions.html	260.33 KB	-rw-r--r--
functools.html	92.96 KB	-rw-r--r--
gc.html	40.97 KB	-rw-r--r--
getopt.html	29.4 KB	-rw-r--r--
getpass.html	16.01 KB	-rw-r--r--
gettext.html	98.02 KB	-rw-r--r--
glob.html	27.2 KB	-rw-r--r--
graphlib.html	34.82 KB	-rw-r--r--
grp.html	16.03 KB	-rw-r--r--
gzip.html	45.65 KB	-rw-r--r--
hashlib.html	93.19 KB	-rw-r--r--
heapq.html	42.43 KB	-rw-r--r--
hmac.html	24.74 KB	-rw-r--r--
html.entities.html	14.91 KB	-rw-r--r--
html.html	14.81 KB	-rw-r--r--
html.parser.html	47.7 KB	-rw-r--r--
http.client.html	85.63 KB	-rw-r--r--
http.cookiejar.html	113.94 KB	-rw-r--r--
http.cookies.html	47.64 KB	-rw-r--r--
http.html	45.52 KB	-rw-r--r--
http.server.html	73.05 KB	-rw-r--r--
i18n.html	13.44 KB	-rw-r--r--
idle.html	77.18 KB	-rw-r--r--
imaplib.html	87.08 KB	-rw-r--r--
imghdr.html	17.94 KB	-rw-r--r--
imp.html	54.32 KB	-rw-r--r--
importlib.html	239.96 KB	-rw-r--r--
importlib.metadata.html	43.14 KB	-rw-r--r--
index.html	75.06 KB	-rw-r--r--
inspect.html	168.74 KB	-rw-r--r--
internet.html	29.89 KB	-rw-r--r--
intro.html	13.81 KB	-rw-r--r--
io.html	154.15 KB	-rw-r--r--
ipaddress.html	137.75 KB	-rw-r--r--
ipc.html	12.6 KB	-rw-r--r--
itertools.html	153.27 KB	-rw-r--r--
json.html	98.9 KB	-rw-r--r--
keyword.html	14.88 KB	-rw-r--r--
language.html	16.71 KB	-rw-r--r--
linecache.html	18.09 KB	-rw-r--r--
locale.html	77.35 KB	-rw-r--r--
logging.config.html	100.3 KB	-rw-r--r--
logging.handlers.html	146.28 KB	-rw-r--r--
logging.html	169.67 KB	-rw-r--r--
lzma.html	66.89 KB	-rw-r--r--
mailbox.html	176.34 KB	-rw-r--r--
mailcap.html	20.86 KB	-rw-r--r--
markup.html	22.31 KB	-rw-r--r--
marshal.html	24.43 KB	-rw-r--r--
math.html	85.82 KB	-rw-r--r--
mimetypes.html	40.27 KB	-rw-r--r--
mm.html	11.16 KB	-rw-r--r--
mmap.html	55.53 KB	-rw-r--r--
modulefinder.html	23.67 KB	-rw-r--r--
modules.html	15.88 KB	-rw-r--r--
msilib.html	78.38 KB	-rw-r--r--
msvcrt.html	29.22 KB	-rw-r--r--
multiprocessing.html	405.24 KB	-rw-r--r--
multiprocessing.shared_memory....	60 KB	-rw-r--r--
netdata.html	20.24 KB	-rw-r--r--
netrc.html	20.39 KB	-rw-r--r--
nis.html	16.76 KB	-rw-r--r--
nntplib.html	84.93 KB	-rw-r--r--
numbers.html	45.67 KB	-rw-r--r--
numeric.html	19.29 KB	-rw-r--r--
operator.html	107.32 KB	-rw-r--r--
optparse.html	256.96 KB	-rw-r--r--
os.html	594.39 KB	-rw-r--r--
os.path.html	65.54 KB	-rw-r--r--
ossaudiodev.html	56.35 KB	-rw-r--r--
pathlib.html	170.01 KB	-rw-r--r--
pdb.html	68.67 KB	-rw-r--r--
persistence.html	19.13 KB	-rw-r--r--
pickle.html	154.45 KB	-rw-r--r--
pickletools.html	22.92 KB	-rw-r--r--
pipes.html	21.7 KB	-rw-r--r--
pkgutil.html	42.76 KB	-rw-r--r--
platform.html	45.08 KB	-rw-r--r--
plistlib.html	30.06 KB	-rw-r--r--
poplib.html	41.42 KB	-rw-r--r--
posix.html	20.96 KB	-rw-r--r--
pprint.html	55.35 KB	-rw-r--r--
profile.html	84.63 KB	-rw-r--r--
pty.html	23.7 KB	-rw-r--r--
pwd.html	16.84 KB	-rw-r--r--
py_compile.html	29 KB	-rw-r--r--
pyclbr.html	24.06 KB	-rw-r--r--
pydoc.html	19.59 KB	-rw-r--r--
pyexpat.html	104.38 KB	-rw-r--r--
python.html	22.46 KB	-rw-r--r--
queue.html	43.39 KB	-rw-r--r--
quopri.html	18.64 KB	-rw-r--r--
random.html	86.31 KB	-rw-r--r--
re.html	214.24 KB	-rw-r--r--
readline.html	50.19 KB	-rw-r--r--
reprlib.html	30.85 KB	-rw-r--r--
resource.html	48.26 KB	-rw-r--r--
rlcompleter.html	18.06 KB	-rw-r--r--
runpy.html	30.99 KB	-rw-r--r--
sched.html	27.04 KB	-rw-r--r--
secrets.html	30.2 KB	-rw-r--r--
security_warnings.html	16.21 KB	-rw-r--r--
select.html	74.58 KB	-rw-r--r--
selectors.html	41.91 KB	-rw-r--r--
shelve.html	36.54 KB	-rw-r--r--
shlex.html	61.03 KB	-rw-r--r--
shutil.html	100.13 KB	-rw-r--r--
signal.html	95.39 KB	-rw-r--r--
site.html	38.16 KB	-rw-r--r--
smtpd.html	44.09 KB	-rw-r--r--
smtplib.html	81.4 KB	-rw-r--r--
sndhdr.html	16.4 KB	-rw-r--r--
socket.html	256.95 KB	-rw-r--r--
socketserver.html	91.95 KB	-rw-r--r--
spwd.html	16.71 KB	-rw-r--r--
sqlite3.html	225.51 KB	-rw-r--r--
ssl.html	328.83 KB	-rw-r--r--
stat.html	57.79 KB	-rw-r--r--
statistics.html	123.22 KB	-rw-r--r--
stdtypes.html	615.43 KB	-rw-r--r--
string.html	108.03 KB	-rw-r--r--
stringprep.html	24.94 KB	-rw-r--r--
struct.html	70.58 KB	-rw-r--r--
subprocess.html	199.03 KB	-rw-r--r--
sunau.html	39.84 KB	-rw-r--r--
superseded.html	26.21 KB	-rw-r--r--
symtable.html	33.26 KB	-rw-r--r--
sys.html	198.83 KB	-rw-r--r--
sysconfig.html	39.81 KB	-rw-r--r--
syslog.html	27.36 KB	-rw-r--r--
tabnanny.html	16.18 KB	-rw-r--r--
tarfile.html	161.92 KB	-rw-r--r--
telnetlib.html	38.21 KB	-rw-r--r--
tempfile.html	58.39 KB	-rw-r--r--
termios.html	22.86 KB	-rw-r--r--
test.html	222.85 KB	-rw-r--r--
text.html	16.8 KB	-rw-r--r--
textwrap.html	48.83 KB	-rw-r--r--
threading.html	128.33 KB	-rw-r--r--
time.html	107.46 KB	-rw-r--r--
timeit.html	52.63 KB	-rw-r--r--
tk.html	28.08 KB	-rw-r--r--
tkinter.colorchooser.html	14.49 KB	-rw-r--r--
tkinter.dnd.html	17.09 KB	-rw-r--r--
tkinter.font.html	22.21 KB	-rw-r--r--
tkinter.html	106.85 KB	-rw-r--r--
tkinter.messagebox.html	20.09 KB	-rw-r--r--
tkinter.scrolledtext.html	14.52 KB	-rw-r--r--
tkinter.tix.html	59.69 KB	-rw-r--r--
tkinter.ttk.html	138.37 KB	-rw-r--r--
token.html	45.73 KB	-rw-r--r--
tokenize.html	39.86 KB	-rw-r--r--
trace.html	38.85 KB	-rw-r--r--
traceback.html	75.61 KB	-rw-r--r--
tracemalloc.html	122.33 KB	-rw-r--r--
tty.html	14.46 KB	-rw-r--r--
turtle.html	271.71 KB	-rw-r--r--
types.html	64.85 KB	-rw-r--r--
typing.html	315.69 KB	-rw-r--r--
unicodedata.html	27.3 KB	-rw-r--r--
unittest.html	310.01 KB	-rw-r--r--
unittest.mock-examples.html	177.75 KB	-rw-r--r--
unittest.mock.html	363.51 KB	-rw-r--r--
unix.html	13.46 KB	-rw-r--r--
urllib.error.html	18.56 KB	-rw-r--r--
urllib.html	12.92 KB	-rw-r--r--
urllib.parse.html	104.65 KB	-rw-r--r--
urllib.request.html	208.87 KB	-rw-r--r--
urllib.robotparser.html	22.63 KB	-rw-r--r--
uu.html	18.2 KB	-rw-r--r--
uuid.html	42.88 KB	-rw-r--r--
venv.html	90.43 KB	-rw-r--r--
warnings.html	69.13 KB	-rw-r--r--
wave.html	36.12 KB	-rw-r--r--
weakref.html	73.36 KB	-rw-r--r--
webbrowser.html	33.98 KB	-rw-r--r--
windows.html	12.32 KB	-rw-r--r--
winreg.html	89.48 KB	-rw-r--r--
winsound.html	26.3 KB	-rw-r--r--
wsgiref.html	111.52 KB	-rw-r--r--
xdrlib.html	42.07 KB	-rw-r--r--
xml.dom.html	114.66 KB	-rw-r--r--
xml.dom.minidom.html	49.6 KB	-rw-r--r--
xml.dom.pulldom.html	30.06 KB	-rw-r--r--
xml.etree.elementtree.html	186.49 KB	-rw-r--r--
xml.html	22.34 KB	-rw-r--r--
xml.sax.handler.html	55.78 KB	-rw-r--r--
xml.sax.html	31.74 KB	-rw-r--r--
xml.sax.reader.html	56.23 KB	-rw-r--r--
xml.sax.utils.html	22.28 KB	-rw-r--r--
xmlrpc.client.html	79.73 KB	-rw-r--r--
xmlrpc.html	11.9 KB	-rw-r--r--
xmlrpc.server.html	63.56 KB	-rw-r--r--
zipapp.html	52.45 KB	-rw-r--r--
zipfile.html	116.59 KB	-rw-r--r--
zipimport.html	33.76 KB	-rw-r--r--
zlib.html	42.29 KB	-rw-r--r--
zoneinfo.html	57.25 KB	-rw-r--r--

Code Editor : selectors.html

<!DOCTYPE html>

<title>selectors — High-level I/O multiplexing &#8212; Python 3.10.12 documentation</title><meta name="viewport" content="width=device-width, initial-scale=1.0">
 
 <link rel="stylesheet" type="text/css" href="../_static/pygments.css" />
 <link rel="stylesheet" type="text/css" href="../_static/pydoctheme.css?2022.1" />
 
 <script data-url_root="../" id="documentation_options" src="../_static/documentation_options.js"></script>
 <script src="../_static/jquery.js"></script>
 <script src="../_static/underscore.js"></script>
 <script src="../_static/doctools.js"></script>
 
 <script src="../_static/sidebar.js"></script>
 
 <link rel="search" type="application/opensearchdescription+xml"
 title="Search within Python 3.10.12 documentation"
 href="../_static/opensearch.xml"/>
 <link rel="author" title="About these documents" href="../about.html" />
 <link rel="index" title="Index" href="../genindex.html" />
 <link rel="search" title="Search" href="../search.html" />
 <link rel="copyright" title="Copyright" href="../copyright.html" />
 <link rel="next" title="signal — Set handlers for asynchronous events" href="signal.html" />
 <link rel="prev" title="select — Waiting for I/O completion" href="select.html" />
 <link rel="canonical" href="file:///usr/share/doc/python3.10/html/library/selectors.html" />

</head>
<body>
<div class="mobile-nav">
 <input type="checkbox" id="menuToggler" class="toggler__input" aria-controls="navigation"
 aria-pressed="false" aria-expanded="false" role="button" aria-label="Menu" />
 <label for="menuToggler" class="toggler__label">
 
 </label>
 <nav class="nav-content" role="navigation">
 <a href="https://www.python.org/" class="nav-logo">
 <img src="../_static/py.svg" alt="Logo"/>
 </a>
 <div class="version_switcher_placeholder"></div>
 <form role="search" class="search" action="../search.html" method="get">
 <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" class="search-icon">
 <path fill-rule="nonzero"
 d="M15.5 14h-.79l-.28-.27a6.5 6.5 0 001.48-5.34c-.47-2.78-2.79-5-5.59-5.34a6.505 6.505 0 00-7.27 7.27c.34 2.8 2.56 5.12 5.34 5.59a6.5 6.5 0 005.34-1.48l.27.28v.79l4.25 4.25c.41.41 1.08.41 1.49 0 .41-.41.41-1.08 0-1.49L15.5 14zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z" fill="#444"></path>
 </svg>
 <input type="text" name="q" aria-label="Quick search"/>
 <input type="submit" value="Go"/>
 </form>
 </nav>
 <div class="menu-wrapper">
 <nav class="menu" role="navigation" aria-label="main navigation">
 <div class="language_switcher_placeholder"></div>
 <h3><a href="../contents.html">Table of Contents</a></h3>
 <ul>
<li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate">selectors</code> — High-level I/O multiplexing</a><ul>
<li><a class="reference internal" href="#introduction">Introduction</a></li>
<li><a class="reference internal" href="#classes">Classes</a></li>
<li><a class="reference internal" href="#examples">Examples</a></li>
</ul>
</li>
</ul>

<div class="related" role="navigation" aria-label="related navigation">
 <h3>Navigation</h3>
 <ul>
 <li class="right" style="margin-right: 10px">
 <a href="../genindex.html" title="General Index"
 accesskey="I">index</a></li>
 <li class="right" >
 <a href="../py-modindex.html" title="Python Module Index"
 >modules</a> |</li>
 <li class="right" >
 <a href="signal.html" title="signal — Set handlers for asynchronous events"
 accesskey="N">next</a> |</li>
 <li class="right" >
 <a href="select.html" title="select — Waiting for I/O completion"
 accesskey="P">previous</a> |</li>

<li><img src="../_static/py.svg" alt="python logo" style="vertical-align: middle; margin-top: -1px"/></li>
 <li><a href="https://www.python.org/">Python</a> &#187;</li>
 <li class="switchers">
 <div class="language_switcher_placeholder"></div>
 <div class="version_switcher_placeholder"></div>
 </li>
 <li>
 
 </li>
 <li id="cpython-language-and-version">
 <a href="../index.html">3.10.12 Documentation</a> &#187;
 </li>

<li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> &#187;</li>
 <li class="nav-item nav-item-2"><a href="ipc.html" accesskey="U">Networking and Interprocess Communication</a> &#187;</li>
 <li class="nav-item nav-item-this"><a href=""><code class="xref py py-mod docutils literal notranslate">selectors</code> — High-level I/O multiplexing</a></li>
 <li class="right">

<div class="document">
 <div class="documentwrapper">
 <div class="bodywrapper">
 <div class="body" role="main">
 
 <section id="module-selectors">
<h1><a class="reference internal" href="#module-selectors" title="selectors: High-level I/O multiplexing."><code class="xref py py-mod docutils literal notranslate">selectors</code></a> — High-level I/O multiplexing<a class="headerlink" href="#module-selectors" title="Permalink to this headline">¶</a></h1>
<div class="versionadded">
New in version 3.4.
</div>
Source code: <a class="reference external" href="https://github.com/python/cpython/tree/3.10/Lib/selectors.py">Lib/selectors.py</a>
<hr class="docutils" />
<section id="introduction">
<h2>Introduction<a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h2>
This module allows high-level and efficient I/O multiplexing, built upon the
<a class="reference internal" href="select.html#module-select" title="select: Wait for I/O completion on multiple streams."><code class="xref py py-mod docutils literal notranslate">select</code></a> module primitives. Users are encouraged to use this module
instead, unless they want precise control over the OS-level primitives used.
It defines a <a class="reference internal" href="#selectors.BaseSelector" title="selectors.BaseSelector"><code class="xref py py-class docutils literal notranslate">BaseSelector</code></a> abstract base class, along with several
concrete implementations (<a class="reference internal" href="#selectors.KqueueSelector" title="selectors.KqueueSelector"><code class="xref py py-class docutils literal notranslate">KqueueSelector</code></a>, <a class="reference internal" href="#selectors.EpollSelector" title="selectors.EpollSelector"><code class="xref py py-class docutils literal notranslate">EpollSelector</code></a>…),
that can be used to wait for I/O readiness notification on multiple file
objects. In the following, “file object” refers to any object with a
<code class="xref py py-meth docutils literal notranslate">fileno()</code> method, or a raw file descriptor. See <a class="reference internal" href="../glossary.html#term-file-object">file object</a>.
<a class="reference internal" href="#selectors.DefaultSelector" title="selectors.DefaultSelector"><code class="xref py py-class docutils literal notranslate">DefaultSelector</code></a> is an alias to the most efficient implementation
available on the current platform: this should be the default choice for most
users.
<div class="admonition note">
Note
The type of file objects supported depends on the platform: on Windows,
sockets are supported, but not pipes, whereas on Unix, both are supported
(some other types may be supported as well, such as fifos or special file
devices).
</div>
<div class="admonition seealso">
See also
<dl class="simple">
<dt><a class="reference internal" href="select.html#module-select" title="select: Wait for I/O completion on multiple streams."><code class="xref py py-mod docutils literal notranslate">select</code></a></dt><dd>Low-level I/O multiplexing module.
</dd>
</dl>
</div>
</section>
<section id="classes">
<h2>Classes<a class="headerlink" href="#classes" title="Permalink to this headline">¶</a></h2>
Classes hierarchy:
<div class="highlight-python3 notranslate"><div class="highlight"><pre>BaseSelector
+-- SelectSelector
+-- PollSelector
+-- EpollSelector
+-- DevpollSelector
+-- KqueueSelector
</pre></div>
</div>
In the following, events is a bitwise mask indicating which I/O events should
be waited for on a given file object. It can be a combination of the modules
constants below:
<blockquote>
<div><table class="docutils align-default">
<colgroup>
<col style="width: 33%" />
<col style="width: 67%" />
</colgroup>
<thead>
<tr class="row-odd"><th class="head">Constant</th>
<th class="head">Meaning</th>
</tr>
</thead>
<tbody>
<tr class="row-even"><td><code class="xref py py-const docutils literal notranslate">EVENT_READ</code></td>
<td>Available for read</td>
</tr>
<tr class="row-odd"><td><code class="xref py py-const docutils literal notranslate">EVENT_WRITE</code></td>
<td>Available for write</td>
</tr>
</tbody>
</table>
</div></blockquote>
<dl class="py class">
<dt class="sig sig-object py" id="selectors.SelectorKey">
class selectors.SelectorKey<a class="headerlink" href="#selectors.SelectorKey" title="Permalink to this definition">¶</a></dt>
<dd>A <a class="reference internal" href="#selectors.SelectorKey" title="selectors.SelectorKey"><code class="xref py py-class docutils literal notranslate">SelectorKey</code></a> is a <a class="reference internal" href="collections.html#collections.namedtuple" title="collections.namedtuple"><code class="xref py py-class docutils literal notranslate">namedtuple</code></a> used to
associate a file object to its underlying file descriptor, selected event
mask and attached data. It is returned by several <a class="reference internal" href="#selectors.BaseSelector" title="selectors.BaseSelector"><code class="xref py py-class docutils literal notranslate">BaseSelector</code></a>
methods.
<dl class="py attribute">
<dt class="sig sig-object py" id="selectors.SelectorKey.fileobj">
fileobj<a class="headerlink" href="#selectors.SelectorKey.fileobj" title="Permalink to this definition">¶</a></dt>
<dd>File object registered.
</dd></dl>

<dl class="py attribute">
<dt class="sig sig-object py" id="selectors.SelectorKey.fd">
fd<a class="headerlink" href="#selectors.SelectorKey.fd" title="Permalink to this definition">¶</a></dt>
<dd>Underlying file descriptor.
</dd></dl>

<dl class="py attribute">
<dt class="sig sig-object py" id="selectors.SelectorKey.events">
events<a class="headerlink" href="#selectors.SelectorKey.events" title="Permalink to this definition">¶</a></dt>
<dd>Events that must be waited for on this file object.
</dd></dl>

<dl class="py attribute">
<dt class="sig sig-object py" id="selectors.SelectorKey.data">
data<a class="headerlink" href="#selectors.SelectorKey.data" title="Permalink to this definition">¶</a></dt>
<dd>Optional opaque data associated to this file object: for example, this
could be used to store a per-client session ID.
</dd></dl>

</dd></dl>

<dl class="py class">
<dt class="sig sig-object py" id="selectors.BaseSelector">
class selectors.BaseSelector<a class="headerlink" href="#selectors.BaseSelector" title="Permalink to this definition">¶</a></dt>
<dd>A <a class="reference internal" href="#selectors.BaseSelector" title="selectors.BaseSelector"><code class="xref py py-class docutils literal notranslate">BaseSelector</code></a> is used to wait for I/O event readiness on multiple
file objects. It supports file stream registration, unregistration, and a
method to wait for I/O events on those streams, with an optional timeout.
It’s an abstract base class, so cannot be instantiated. Use
<a class="reference internal" href="#selectors.DefaultSelector" title="selectors.DefaultSelector"><code class="xref py py-class docutils literal notranslate">DefaultSelector</code></a> instead, or one of <a class="reference internal" href="#selectors.SelectSelector" title="selectors.SelectSelector"><code class="xref py py-class docutils literal notranslate">SelectSelector</code></a>,
<a class="reference internal" href="#selectors.KqueueSelector" title="selectors.KqueueSelector"><code class="xref py py-class docutils literal notranslate">KqueueSelector</code></a> etc. if you want to specifically use an
implementation, and your platform supports it.
<a class="reference internal" href="#selectors.BaseSelector" title="selectors.BaseSelector"><code class="xref py py-class docutils literal notranslate">BaseSelector</code></a> and its concrete implementations support the
<a class="reference internal" href="../glossary.html#term-context-manager">context manager</a> protocol.
<dl class="py method">
<dt class="sig sig-object py" id="selectors.BaseSelector.register">
abstractmethod register(fileobj, events, data=None)<a class="headerlink" href="#selectors.BaseSelector.register" title="Permalink to this definition">¶</a></dt>
<dd>Register a file object for selection, monitoring it for I/O events.
fileobj is the file object to monitor. It may either be an integer
file descriptor or an object with a <code class="docutils literal notranslate">fileno()</code> method.
events is a bitwise mask of events to monitor.
data is an opaque object.
This returns a new <a class="reference internal" href="#selectors.SelectorKey" title="selectors.SelectorKey"><code class="xref py py-class docutils literal notranslate">SelectorKey</code></a> instance, or raises a
<a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate">ValueError</code></a> in case of invalid event mask or file descriptor, or
<a class="reference internal" href="exceptions.html#KeyError" title="KeyError"><code class="xref py py-exc docutils literal notranslate">KeyError</code></a> if the file object is already registered.
</dd></dl>

<dl class="py method">
<dt class="sig sig-object py" id="selectors.BaseSelector.unregister">
abstractmethod unregister(fileobj)<a class="headerlink" href="#selectors.BaseSelector.unregister" title="Permalink to this definition">¶</a></dt>
<dd>Unregister a file object from selection, removing it from monitoring. A
file object shall be unregistered prior to being closed.
fileobj must be a file object previously registered.
This returns the associated <a class="reference internal" href="#selectors.SelectorKey" title="selectors.SelectorKey"><code class="xref py py-class docutils literal notranslate">SelectorKey</code></a> instance, or raises a
<a class="reference internal" href="exceptions.html#KeyError" title="KeyError"><code class="xref py py-exc docutils literal notranslate">KeyError</code></a> if fileobj is not registered. It will raise
<a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate">ValueError</code></a> if fileobj is invalid (e.g. it has no <code class="docutils literal notranslate">fileno()</code>
method or its <code class="docutils literal notranslate">fileno()</code> method has an invalid return value).
</dd></dl>

<dl class="py method">
<dt class="sig sig-object py" id="selectors.BaseSelector.modify">
modify(fileobj, events, data=None)<a class="headerlink" href="#selectors.BaseSelector.modify" title="Permalink to this definition">¶</a></dt>
<dd>Change a registered file object’s monitored events or attached data.
This is equivalent to <code class="xref py py-meth docutils literal notranslate">BaseSelector.unregister(fileobj)()</code> followed
by <code class="xref py py-meth docutils literal notranslate">BaseSelector.register(fileobj, events, data)()</code>, except that it
can be implemented more efficiently.
This returns a new <a class="reference internal" href="#selectors.SelectorKey" title="selectors.SelectorKey"><code class="xref py py-class docutils literal notranslate">SelectorKey</code></a> instance, or raises a
<a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate">ValueError</code></a> in case of invalid event mask or file descriptor, or
<a class="reference internal" href="exceptions.html#KeyError" title="KeyError"><code class="xref py py-exc docutils literal notranslate">KeyError</code></a> if the file object is not registered.
</dd></dl>

<dl class="py method">
<dt class="sig sig-object py" id="selectors.BaseSelector.select">
abstractmethod select(timeout=None)<a class="headerlink" href="#selectors.BaseSelector.select" title="Permalink to this definition">¶</a></dt>
<dd>Wait until some registered file objects become ready, or the timeout
expires.
If <code class="docutils literal notranslate">timeout &gt; 0</code>, this specifies the maximum wait time, in seconds.
If <code class="docutils literal notranslate">timeout &lt;= 0</code>, the call won’t block, and will report the currently
ready file objects.
If timeout is <code class="docutils literal notranslate">None</code>, the call will block until a monitored file object
becomes ready.
This returns a list of <code class="docutils literal notranslate">(key, events)</code> tuples, one for each ready file
object.
key is the <a class="reference internal" href="#selectors.SelectorKey" title="selectors.SelectorKey"><code class="xref py py-class docutils literal notranslate">SelectorKey</code></a> instance corresponding to a ready file
object.
events is a bitmask of events ready on this file object.
<div class="admonition note">
Note
This method can return before any file object becomes ready or the
timeout has elapsed if the current process receives a signal: in this
case, an empty list will be returned.
</div>
<div class="versionchanged">
Changed in version 3.5: The selector is now retried with a recomputed timeout when interrupted
by a signal if the signal handler did not raise an exception (see
<a class="pep reference external" href="https://www.python.org/dev/peps/pep-0475">PEP 475</a> for the rationale), instead of returning an empty list
of events before the timeout.
</div>
</dd></dl>

<dl class="py method">
<dt class="sig sig-object py" id="selectors.BaseSelector.close">
close()<a class="headerlink" href="#selectors.BaseSelector.close" title="Permalink to this definition">¶</a></dt>
<dd>Close the selector.
This must be called to make sure that any underlying resource is freed.
The selector shall not be used once it has been closed.
</dd></dl>

<dl class="py method">
<dt class="sig sig-object py" id="selectors.BaseSelector.get_key">
get_key(fileobj)<a class="headerlink" href="#selectors.BaseSelector.get_key" title="Permalink to this definition">¶</a></dt>
<dd>Return the key associated with a registered file object.
This returns the <a class="reference internal" href="#selectors.SelectorKey" title="selectors.SelectorKey"><code class="xref py py-class docutils literal notranslate">SelectorKey</code></a> instance associated to this file
object, or raises <a class="reference internal" href="exceptions.html#KeyError" title="KeyError"><code class="xref py py-exc docutils literal notranslate">KeyError</code></a> if the file object is not registered.
</dd></dl>

<dl class="py method">
<dt class="sig sig-object py" id="selectors.BaseSelector.get_map">
abstractmethod get_map()<a class="headerlink" href="#selectors.BaseSelector.get_map" title="Permalink to this definition">¶</a></dt>
<dd>Return a mapping of file objects to selector keys.
This returns a <a class="reference internal" href="collections.abc.html#collections.abc.Mapping" title="collections.abc.Mapping"><code class="xref py py-class docutils literal notranslate">Mapping</code></a> instance mapping
registered file objects to their associated <a class="reference internal" href="#selectors.SelectorKey" title="selectors.SelectorKey"><code class="xref py py-class docutils literal notranslate">SelectorKey</code></a>
instance.
</dd></dl>

</dd></dl>

<dl class="py class">
<dt class="sig sig-object py" id="selectors.DefaultSelector">
class selectors.DefaultSelector<a class="headerlink" href="#selectors.DefaultSelector" title="Permalink to this definition">¶</a></dt>
<dd>The default selector class, using the most efficient implementation
available on the current platform. This should be the default choice for
most users.
</dd></dl>

<dl class="py class">
<dt class="sig sig-object py" id="selectors.SelectSelector">
class selectors.SelectSelector<a class="headerlink" href="#selectors.SelectSelector" title="Permalink to this definition">¶</a></dt>
<dd><a class="reference internal" href="select.html#select.select" title="select.select"><code class="xref py py-func docutils literal notranslate">select.select()</code></a>-based selector.
</dd></dl>

<dl class="py class">
<dt class="sig sig-object py" id="selectors.PollSelector">
class selectors.PollSelector<a class="headerlink" href="#selectors.PollSelector" title="Permalink to this definition">¶</a></dt>
<dd><a class="reference internal" href="select.html#select.poll" title="select.poll"><code class="xref py py-func docutils literal notranslate">select.poll()</code></a>-based selector.
</dd></dl>

<dl class="py class">
<dt class="sig sig-object py" id="selectors.EpollSelector">
class selectors.EpollSelector<a class="headerlink" href="#selectors.EpollSelector" title="Permalink to this definition">¶</a></dt>
<dd><a class="reference internal" href="select.html#select.epoll" title="select.epoll"><code class="xref py py-func docutils literal notranslate">select.epoll()</code></a>-based selector.
<dl class="py method">
<dt class="sig sig-object py" id="selectors.EpollSelector.fileno">
fileno()<a class="headerlink" href="#selectors.EpollSelector.fileno" title="Permalink to this definition">¶</a></dt>
<dd>This returns the file descriptor used by the underlying
<a class="reference internal" href="select.html#select.epoll" title="select.epoll"><code class="xref py py-func docutils literal notranslate">select.epoll()</code></a> object.
</dd></dl>

</dd></dl>

<dl class="py class">
<dt class="sig sig-object py" id="selectors.DevpollSelector">
class selectors.DevpollSelector<a class="headerlink" href="#selectors.DevpollSelector" title="Permalink to this definition">¶</a></dt>
<dd><a class="reference internal" href="select.html#select.devpoll" title="select.devpoll"><code class="xref py py-func docutils literal notranslate">select.devpoll()</code></a>-based selector.
<dl class="py method">
<dt class="sig sig-object py" id="selectors.DevpollSelector.fileno">
fileno()<a class="headerlink" href="#selectors.DevpollSelector.fileno" title="Permalink to this definition">¶</a></dt>
<dd>This returns the file descriptor used by the underlying
<a class="reference internal" href="select.html#select.devpoll" title="select.devpoll"><code class="xref py py-func docutils literal notranslate">select.devpoll()</code></a> object.
</dd></dl>

<div class="versionadded">
New in version 3.5.
</div>
</dd></dl>

<dl class="py class">
<dt class="sig sig-object py" id="selectors.KqueueSelector">
class selectors.KqueueSelector<a class="headerlink" href="#selectors.KqueueSelector" title="Permalink to this definition">¶</a></dt>
<dd><a class="reference internal" href="select.html#select.kqueue" title="select.kqueue"><code class="xref py py-func docutils literal notranslate">select.kqueue()</code></a>-based selector.
<dl class="py method">
<dt class="sig sig-object py" id="selectors.KqueueSelector.fileno">
fileno()<a class="headerlink" href="#selectors.KqueueSelector.fileno" title="Permalink to this definition">¶</a></dt>
<dd>This returns the file descriptor used by the underlying
<a class="reference internal" href="select.html#select.kqueue" title="select.kqueue"><code class="xref py py-func docutils literal notranslate">select.kqueue()</code></a> object.
</dd></dl>

</dd></dl>

</section>
<section id="examples">
<h2>Examples<a class="headerlink" href="#examples" title="Permalink to this headline">¶</a></h2>
Here is a simple echo server implementation:
<div class="highlight-python3 notranslate"><div class="highlight"><pre>import selectors
import socket

sel = selectors.DefaultSelector()

def accept(sock, mask):
 conn, addr = sock.accept() # Should be ready
 print(&#39;accepted&#39;, conn, &#39;from&#39;, addr)
 conn.setblocking(False)
 sel.register(conn, selectors.EVENT_READ, read)

def read(conn, mask):
 data = conn.recv(1000) # Should be ready
 if data:
 print(&#39;echoing&#39;, repr(data), &#39;to&#39;, conn)
 conn.send(data) # Hope it won&#39;t block
 else:
 print(&#39;closing&#39;, conn)
 sel.unregister(conn)
 conn.close()

sock = socket.socket()
sock.bind((&#39;localhost&#39;, 1234))
sock.listen(100)
sock.setblocking(False)
sel.register(sock, selectors.EVENT_READ, accept)

while True:
 events = sel.select()
 for key, mask in events:
 callback = key.data
 callback(key.fileobj, mask)
</pre></div>
</div>
</section>
</section>

<div class="clearer"></div>
 </div>
 </div>
 </div>
 <div class="sphinxsidebar" role="navigation" aria-label="main navigation">
 <div class="sphinxsidebarwrapper">
 <h3><a href="../contents.html">Table of Contents</a></h3>
 <ul>
<li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate">selectors</code> — High-level I/O multiplexing</a><ul>
<li><a class="reference internal" href="#introduction">Introduction</a></li>
<li><a class="reference internal" href="#classes">Classes</a></li>
<li><a class="reference internal" href="#examples">Examples</a></li>
</ul>
</li>
</ul>

<h4>Previous topic</h4>
 <a href="select.html"
 title="previous chapter"><code class="xref py py-mod docutils literal notranslate">select</code> — Waiting for I/O completion</a>
 <h4>Next topic</h4>
 <a href="signal.html"
 title="next chapter"><code class="xref py py-mod docutils literal notranslate">signal</code> — Set handlers for asynchronous events</a>
 <div role="note" aria-label="source link">
 <h3>This Page</h3>
 <ul class="this-page-menu">
 <li><a href="../bugs.html">Report a Bug</a></li>
 <li>
 <a href="https://github.com/python/cpython/blob/3.10/Doc/library/selectors.rst"
 rel="nofollow">Show Source
 </a>
 </li>
 </ul>
 </div>
 </div>
 </div>
 <div class="clearer"></div>
 </div> 
 <div class="related" role="navigation" aria-label="related navigation">
 <h3>Navigation</h3>
 <ul>
 <li class="right" style="margin-right: 10px">
 <a href="../genindex.html" title="General Index"
 >index</a></li>
 <li class="right" >
 <a href="../py-modindex.html" title="Python Module Index"
 >modules</a> |</li>
 <li class="right" >
 <a href="signal.html" title="signal — Set handlers for asynchronous events"
 >next</a> |</li>
 <li class="right" >
 <a href="select.html" title="select — Waiting for I/O completion"
 >previous</a> |</li>

<li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> &#187;</li>
 <li class="nav-item nav-item-2"><a href="ipc.html" >Networking and Interprocess Communication</a> &#187;</li>
 <li class="nav-item nav-item-this"><a href=""><code class="xref py py-mod docutils literal notranslate">selectors</code> — High-level I/O multiplexing</a></li>
 <li class="right">

<div class="inline-search" role="search">
 <form class="inline-search" action="../search.html" method="get">
 <input placeholder="Quick search" aria-label="Quick search" type="text" name="q" />
 <input type="submit" value="Go" />
 <input type="hidden" name="check_keywords" value="yes" />
 <input type="hidden" name="area" value="default" />
 </form>
 </div>
 |
 </li>
 
 </ul>
 </div> 
 <div class="footer">
 &copy; <a href="../copyright.html">Copyright</a> 2001-2026, Python Software Foundation.
 
 This page is licensed under the Python Software Foundation License Version 2.
 
 Examples, recipes, and other code in the documentation are additionally licensed under the Zero Clause BSD License.
 
 See <a href="/license.html">History and License</a> for more information.

The Python Software Foundation is a non-profit corporation.
<a href="https://www.python.org/psf/donations/">Please donate.</a>

Last updated on January 26, 2026.
 <a href="/bugs.html">Found a bug</a>?

Created using <a href="https://www.sphinx-doc.org/">Sphinx</a> 4.3.2.
 </div>

</body>
</html>

${this.title}

Code Editor : selectors.html