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href="../changelog_1_4.html">Changes for 1.4</a></li> <li class="toctree-l2"><a class="reference internal" href="../changelog_1_3.html">Changes for 1.3</a></li> <li class="toctree-l2"><a class="reference internal" href="../changelog_1_2.html">Changes for 1.2</a></li> <li class="toctree-l2"><a class="reference internal" href="../changelog_1_1.html">Changes for 1.1</a></li> <li class="toctree-l2"><a class="reference internal" href="../changelog_1_0.html">Changes for 1.0</a></li> <li class="toctree-l2"><a class="reference internal" href="../changelog_pre.html">Changes before gevent 1.0</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="../intro.html">Introduction</a></li> <li class="toctree-l1"><a class="reference internal" href="gevent.html"><code class="xref py py-mod docutils literal notranslate">gevent</code> – common functions</a></li> <li class="toctree-l1"><a class="reference internal" href="gevent.greenlet.html">Greenlet Objects</a></li> <li class="toctree-l1"><a class="reference internal" href="../servers.html">Implementing servers</a></li> <li class="toctree-l1 has-children"><a class="reference internal" href="../dns.html">Name Resolution (DNS)</a><input class="toctree-checkbox" id="toctree-checkbox-2" name="toctree-checkbox-2" role="switch" type="checkbox"/><label for="toctree-checkbox-2"><div class="visually-hidden">Toggle navigation of Name Resolution (DNS)</div><svg><use href="#svg-arrow-right"></use></svg></label><ul> <li class="toctree-l2"><a class="reference internal" href="gevent.resolver.thread.html"><code class="xref py py-mod docutils literal notranslate">gevent.resolver.thread</code> – thread based hostname resolver</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.resolver.ares.html"><code class="xref py py-mod docutils literal notranslate">gevent.resolver.ares</code> – c-ares based hostname resolver</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.resolver.dnspython.html"><code class="xref py py-mod docutils literal notranslate">gevent.resolver.dnspython</code> – Pure Python hostname resolver</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.resolver.blocking.html"><code class="xref py py-mod docutils literal notranslate">gevent.resolver.blocking</code> – Non-cooperative resolver</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="../monitoring.html">Monitoring and Debugging gevent Applications</a></li> <li class="toctree-l1"><a class="reference internal" href="../loop_impls.html">Event Loop Implementations: libuv and libev</a></li> <li class="toctree-l1"><a class="reference internal" href="../configuration.html">Configuring gevent</a></li> </ul> <ul class="current"> <li class="toctree-l1 current has-children"><a class="reference internal" href="index.html">API reference</a><input checked="" class="toctree-checkbox" id="toctree-checkbox-3" name="toctree-checkbox-3" role="switch" type="checkbox"/><label for="toctree-checkbox-3"><div class="visually-hidden">Toggle navigation of API reference</div><svg><use href="#svg-arrow-right"></use></svg></label><ul class="current"> <li class="toctree-l2"><a class="reference internal" href="gevent.html"><code class="xref py py-mod docutils literal notranslate">gevent</code> – common functions</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.timeout.html">Cooperative Timeouts Using <code class="docutils literal notranslate">gevent.Timeout</code></a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.greenlet.html">Greenlet Objects</a></li> <li class="toctree-l2 has-children"><a class="reference internal" href="gevent.socket.html"><code class="xref py py-mod docutils literal notranslate">gevent.socket</code> – Cooperative low-level networking interface</a><input class="toctree-checkbox" id="toctree-checkbox-4" name="toctree-checkbox-4" role="switch" type="checkbox"/><label for="toctree-checkbox-4"><div class="visually-hidden">Toggle navigation of gevent.socket – Cooperative low-level networking interface</div><svg><use href="#svg-arrow-right"></use></svg></label><ul> <li class="toctree-l3"><a class="reference internal" href="gevent._socket3.html">Python 3 interface</a></li> </ul> </li> <li class="toctree-l2"><a class="reference internal" href="gevent.ssl.html"><code class="xref py py-mod docutils literal notranslate">gevent.ssl</code> – Secure Sockets Layer (SSL/TLS) module</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.select.html"><code class="xref py py-mod docutils literal notranslate">gevent.select</code> – Waiting for I/O completion</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.selectors.html"><code class="xref py py-mod docutils literal notranslate">gevent.selectors</code> – High-level IO Multiplexing</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.event.html"><code class="xref py py-mod docutils literal notranslate">gevent.event</code> – Notifications of multiple listeners</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.queue.html"><code class="xref py py-mod docutils literal notranslate">gevent.queue</code> – Synchronized queues</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.local.html"><code class="xref py py-mod docutils literal notranslate">gevent.local</code> – Greenlet-local objects</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.lock.html"><code class="xref py py-mod docutils literal notranslate">gevent.lock</code> – Locking primitives</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.hub.html"><code class="docutils literal notranslate">gevent.hub</code> - The Event Loop and the Hub</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.core.html"><code class="xref py py-mod docutils literal notranslate">gevent.core</code> - (deprecated) event loop abstraction</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.html"><code class="xref py py-mod docutils literal notranslate">gevent</code> – common functions</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.backdoor.html"><code class="xref py py-mod docutils literal notranslate">gevent.backdoor</code> – Interactive greenlet-based network console that can be used in any process</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.baseserver.html"><code class="xref py py-mod docutils literal notranslate">gevent.baseserver</code> – Base class for implementing servers</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.builtins.html"><code class="xref py py-mod docutils literal notranslate">gevent.builtins</code> – gevent friendly implementations of builtin functions</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.contextvars.html"><code class="xref py py-mod docutils literal notranslate">gevent.contextvars</code> – Cooperative <code class="docutils literal notranslate">contextvars</code></a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.core.html"><code class="xref py py-mod docutils literal notranslate">gevent.core</code> - (deprecated) event loop abstraction</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.event.html"><code class="xref py py-mod docutils literal notranslate">gevent.event</code> – Notifications of multiple listeners</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.events.html"><code class="xref py py-mod docutils literal notranslate">gevent.events</code> – Publish/subscribe event infrastructure</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.exceptions.html"><code class="xref py py-mod docutils literal notranslate">gevent.exceptions</code> – Exceptions</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.fileobject.html"><code class="xref py py-mod docutils literal notranslate">gevent.fileobject</code> – Wrappers to make file-like objects cooperative</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.hub.html"><code class="docutils literal notranslate">gevent.hub</code> - The Event Loop and the Hub</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.local.html"><code class="xref py py-mod docutils literal notranslate">gevent.local</code> – Greenlet-local objects</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.lock.html"><code class="xref py py-mod docutils literal notranslate">gevent.lock</code> – Locking primitives</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.monkey.html"><code class="xref py py-mod docutils literal notranslate">gevent.monkey</code> – Make the standard library cooperative</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.os.html"><code class="xref py py-mod docutils literal notranslate">gevent.os</code> – Low-level operating system functions from <code class="xref py py-mod docutils literal notranslate">os</code></a></li> <li class="toctree-l2 current current-page"><a class="current reference internal" href="#"><code class="xref py py-mod docutils literal notranslate">gevent.pool</code> – Managing greenlets in a group</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.pywsgi.html"><code class="xref py py-mod docutils literal notranslate">gevent.pywsgi</code> – A pure-Python, gevent-friendly WSGI server</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.queue.html"><code class="xref py py-mod docutils literal notranslate">gevent.queue</code> – Synchronized queues</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.resolver.ares.html"><code class="xref py py-mod docutils literal notranslate">gevent.resolver.ares</code> – c-ares based hostname resolver</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.resolver.blocking.html"><code class="xref py py-mod docutils literal notranslate">gevent.resolver.blocking</code> – Non-cooperative resolver</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.resolver.dnspython.html"><code class="xref py py-mod docutils literal notranslate">gevent.resolver.dnspython</code> – Pure Python hostname resolver</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.resolver.thread.html"><code class="xref py py-mod docutils literal notranslate">gevent.resolver.thread</code> – thread based hostname resolver</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.select.html"><code class="xref py py-mod docutils literal notranslate">gevent.select</code> – Waiting for I/O completion</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.selectors.html"><code class="xref py py-mod docutils literal notranslate">gevent.selectors</code> – High-level IO Multiplexing</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.server.html"><code class="xref py py-mod docutils literal notranslate">gevent.server</code> – TCP/SSL server</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.signal.html"><code class="xref py py-mod docutils literal notranslate">gevent.signal</code> – Cooperative implementation of special cases of <code class="xref py py-func docutils literal notranslate">signal.signal()</code></a></li> <li class="toctree-l2 has-children"><a class="reference internal" href="gevent.socket.html"><code class="xref py py-mod docutils literal notranslate">gevent.socket</code> – Cooperative low-level networking interface</a><input class="toctree-checkbox" id="toctree-checkbox-5" name="toctree-checkbox-5" role="switch" type="checkbox"/><label 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docutils literal notranslate">thread</code> module that spawns greenlets</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.threading.html"><code class="xref py py-mod docutils literal notranslate">gevent.threading</code> – Implementation of the standard <code class="xref py py-mod docutils literal notranslate">threading</code> using greenlets</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.threadpool.html"><code class="xref py py-mod docutils literal notranslate">gevent.threadpool</code> - A pool of native threads</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.time.html"><code class="xref py py-mod docutils literal notranslate">gevent.time</code> – Makes sleep gevent aware</a></li> <li class="toctree-l2"><a class="reference internal" href="gevent.util.html"><code class="xref py py-mod docutils literal notranslate">gevent.util</code> – Low-level utilities</a></li> <li class="toctree-l2"><a class="reference 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<svg class="theme-icon-when-auto-light"><use href="#svg-sun-with-moon"></use></svg> <svg class="theme-icon-when-auto-dark"><use href="#svg-moon-with-sun"></use></svg> <svg class="theme-icon-when-dark"><use href="#svg-moon"></use></svg> <svg class="theme-icon-when-light"><use href="#svg-sun"></use></svg> </button> </div> <label class="toc-overlay-icon toc-content-icon" for="__toc"> <div class="visually-hidden">Toggle table of contents sidebar</div> <svg><use href="#svg-toc"></use></svg> </label> </div> <article role="main" id="furo-main-content"> <section id="module-gevent.pool"> <h1><a class="reference internal" href="#module-gevent.pool" title="gevent.pool"><code class="xref py py-mod docutils literal notranslate">gevent.pool</code></a> – Managing greenlets in a group<a class="headerlink" href="#module-gevent.pool" title="Link to this heading">¶</a></h1> <dl class="py class"> <dt class="sig sig-object py" id="gevent.pool.Group"> class Group(*args)<a class="reference internal" href="../_modules/gevent/pool.html#Group">[source]</a><a class="headerlink" href="#gevent.pool.Group" title="Link to this definition">¶</a></dt> <dd>Bases: <code class="xref py py-class docutils literal notranslate">GroupMappingMixin</code> Maintain a group of greenlets that are still running, without limiting their number. Links to each item and removes it upon notification. Groups can be iterated to discover what greenlets they are tracking, they can be tested to see if they contain a greenlet, and they know the number (len) of greenlets they are tracking. If they are not tracking any greenlets, they are False in a boolean context. <dl class="py attribute"> <dt class="sig sig-object py" id="gevent.pool.Group.greenlet_class"> greenlet_class<a class="headerlink" href="#gevent.pool.Group.greenlet_class" title="Link to this definition">¶</a></dt> <dd>Either <a class="reference internal" href="gevent.greenlet.html#gevent.Greenlet" title="gevent.Greenlet"><code class="xref py py-class docutils literal notranslate">gevent.Greenlet</code></a> (the default) or a subclass. These are the type of object we will <a class="reference internal" href="#gevent.pool.Group.spawn" title="gevent.pool.Group.spawn"><code class="xref py py-meth docutils literal notranslate">spawn()</code></a>. This can be changed on an instance or in a subclass. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.__len__"> __len__()<a class="reference internal" href="../_modules/gevent/pool.html#Group.__len__">[source]</a><a class="headerlink" href="#gevent.pool.Group.__len__" title="Link to this definition">¶</a></dt> <dd>Answer how many greenlets we are tracking. Note that if we are empty, we are False in a boolean context. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.__contains__"> __contains__(item)<a class="reference internal" href="../_modules/gevent/pool.html#Group.__contains__">[source]</a><a class="headerlink" href="#gevent.pool.Group.__contains__" title="Link to this definition">¶</a></dt> <dd>Answer if we are tracking the given greenlet. </dd></dl> <dl class="py attribute"> <dt class="sig sig-object py" id="id0"> greenlet_class<a class="headerlink" href="#id0" title="Link to this definition">¶</a></dt> <dd>alias of <code class="xref py py-class docutils literal notranslate">Greenlet</code> </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.add"> add(greenlet)<a class="reference internal" href="../_modules/gevent/pool.html#Group.add">[source]</a><a class="headerlink" href="#gevent.pool.Group.add" title="Link to this definition">¶</a></dt> <dd>Begin tracking the greenlet. If this group is <a class="reference internal" href="#gevent.pool.Group.full" title="gevent.pool.Group.full"><code class="xref py py-meth docutils literal notranslate">full()</code></a>, then this method may block until it is possible to track the greenlet. Typically the greenlet should not be started when it is added because if this object blocks in this method, then the greenlet may run to completion before it is tracked. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.apply"> apply(func, args=None, kwds=None)<a class="headerlink" href="#gevent.pool.Group.apply" title="Link to this definition">¶</a></dt> <dd>Rough quivalent of the <a class="reference internal" href="#gevent.pool.Group.apply" title="gevent.pool.Group.apply"><code class="xref py py-func docutils literal notranslate">apply()</code></a> builtin function blocking until the result is ready and returning it. The <code class="docutils literal notranslate">func</code> will usually, but not always, be run in a way that allows the current greenlet to switch out (for example, in a new greenlet or thread, depending on implementation). But if the current greenlet or thread is already one that was spawned by this pool, the pool may choose to immediately run the <code class="xref py py-obj docutils literal notranslate">func</code> synchronously. Any exception <code class="docutils literal notranslate">func</code> raises will be propagated to the caller of <code class="docutils literal notranslate">apply</code> (that is, this method will raise the exception that <code class="docutils literal notranslate">func</code> raised). </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.apply_async"> apply_async(func, args=None, kwds=None, callback=None)<a class="headerlink" href="#gevent.pool.Group.apply_async" title="Link to this definition">¶</a></dt> <dd>A variant of the <a class="reference internal" href="#gevent.pool.Group.apply" title="gevent.pool.Group.apply"><code class="xref py py-meth docutils literal notranslate">apply()</code></a> method which returns a <a class="reference internal" href="gevent.greenlet.html#gevent.Greenlet" title="gevent.Greenlet"><code class="xref py py-class docutils literal notranslate">Greenlet</code></a> object. When the returned greenlet gets to run, it will call <a class="reference internal" href="#gevent.pool.Group.apply" title="gevent.pool.Group.apply"><code class="xref py py-meth docutils literal notranslate">apply()</code></a>, passing in func, args and kwds. If callback is specified, then it should be a callable which accepts a single argument. When the result becomes ready callback is applied to it (unless the call failed). This method will never block, even if this group is full (that is, even if <a class="reference internal" href="#gevent.pool.Group.spawn" title="gevent.pool.Group.spawn"><code class="xref py py-meth docutils literal notranslate">spawn()</code></a> would block, this method will not). <div class="admonition caution"> Caution The returned greenlet may or may not be tracked as part of this group, so <a class="reference internal" href="#gevent.pool.Group.join" title="gevent.pool.Group.join"><code class="xref py py-meth docutils literal notranslate">joining</code></a> this group is not a reliable way to wait for the results to be available or for the returned greenlet to run; instead, join the returned greenlet. </div> <div class="admonition tip"> Tip Because <a class="reference internal" href="gevent.threadpool.html#gevent.threadpool.ThreadPool" title="gevent.threadpool.ThreadPool"><code class="xref py py-class docutils literal notranslate">ThreadPool</code></a> objects do not track greenlets, the returned greenlet will never be a part of it. To reduce overhead and improve performance, <a class="reference internal" href="#gevent.pool.Group" title="gevent.pool.Group"><code class="xref py py-class docutils literal notranslate">Group</code></a> and <a class="reference internal" href="#gevent.pool.Pool" title="gevent.pool.Pool"><code class="xref py py-class docutils literal notranslate">Pool</code></a> may choose to track the returned greenlet. These are implementation details that may change. </div> </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.apply_cb"> apply_cb(func, args=None, kwds=None, callback=None)<a class="headerlink" href="#gevent.pool.Group.apply_cb" title="Link to this definition">¶</a></dt> <dd><a class="reference internal" href="#gevent.pool.Group.apply" title="gevent.pool.Group.apply"><code class="xref py py-meth docutils literal notranslate">apply()</code></a> the given func(*args, **kwds), and, if a callback is given, run it with the results of func (unless an exception was raised.) The callback may be called synchronously or asynchronously. If called asynchronously, it will not be tracked by this group. (<a class="reference internal" href="#gevent.pool.Group" title="gevent.pool.Group"><code class="xref py py-class docutils literal notranslate">Group</code></a> and <a class="reference internal" href="#gevent.pool.Pool" title="gevent.pool.Pool"><code class="xref py py-class docutils literal notranslate">Pool</code></a> call it asynchronously in a new greenlet; <a class="reference internal" href="gevent.threadpool.html#gevent.threadpool.ThreadPool" title="gevent.threadpool.ThreadPool"><code class="xref py py-class docutils literal notranslate">ThreadPool</code></a> calls it synchronously in the current greenlet.) </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.discard"> discard(greenlet)<a class="reference internal" href="../_modules/gevent/pool.html#Group.discard">[source]</a><a class="headerlink" href="#gevent.pool.Group.discard" title="Link to this definition">¶</a></dt> <dd>Stop tracking the greenlet. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.full"> full()<a class="reference internal" href="../_modules/gevent/pool.html#Group.full">[source]</a><a class="headerlink" href="#gevent.pool.Group.full" title="Link to this definition">¶</a></dt> <dd>Return a value indicating whether this group can track more greenlets. In this implementation, because there are no limits on the number of tracked greenlets, this will always return a <code class="docutils literal notranslate">False</code> value. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.imap"> imap(func, *iterables, maxsize=None) → iterable<a class="headerlink" href="#gevent.pool.Group.imap" title="Link to this definition">¶</a></dt> <dd>An equivalent of <code class="xref py py-func docutils literal notranslate">itertools.imap()</code>, operating in parallel. The func is applied to each element yielded from each iterable in iterables in turn, collecting the result. If this object has a bound on the number of active greenlets it can contain (such as <a class="reference internal" href="#gevent.pool.Pool" title="gevent.pool.Pool"><code class="xref py py-class docutils literal notranslate">Pool</code></a>), then at most that number of tasks will operate in parallel. <dl class="field-list simple"> <dt class="field-odd">Parameters:</dt> <dd class="field-odd">maxsize (<a class="reference external" href="https://docs.python.org/3/library/functions.html#int" title="(in Python v3.13)">int</a>) – If given and not-None, specifies the maximum number of finished results that will be allowed to accumulate awaiting the reader; more than that number of results will cause map function greenlets to begin to block. This is most useful if there is a great disparity in the speed of the mapping code and the consumer and the results consume a great deal of resources. <div class="admonition note"> Note This is separate from any bound on the number of active parallel tasks, though they may have some interaction (for example, limiting the number of parallel tasks to the smallest bound). </div> <div class="admonition note"> Note Using a bound is slightly more computationally expensive than not using a bound. </div> <div class="admonition tip"> Tip The <a class="reference internal" href="#gevent.pool.Group.imap_unordered" title="gevent.pool.Group.imap_unordered"><code class="xref py py-meth docutils literal notranslate">imap_unordered()</code></a> method makes much better use of this parameter. Some additional, unspecified, number of objects may be required to be kept in memory to maintain order by this function. </div> </dd> <dt class="field-even">Returns:</dt> <dd class="field-even">An iterable object. </dd> </dl> <div class="versionchanged"> Changed in version 1.1b3: Added the maxsize keyword parameter. </div> <div class="versionchanged"> Changed in version 1.1a1: Accept multiple iterables to iterate in parallel. </div> </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.imap_unordered"> imap_unordered(func, *iterables, maxsize=None) → iterable<a class="headerlink" href="#gevent.pool.Group.imap_unordered" title="Link to this definition">¶</a></dt> <dd>The same as <a class="reference internal" href="#gevent.pool.Group.imap" title="gevent.pool.Group.imap"><code class="xref py py-meth docutils literal notranslate">imap()</code></a> except that the ordering of the results from the returned iterator should be considered in arbitrary order. This is lighter weight than <a class="reference internal" href="#gevent.pool.Group.imap" title="gevent.pool.Group.imap"><code class="xref py py-meth docutils literal notranslate">imap()</code></a> and should be preferred if order doesn’t matter. <div class="admonition seealso"> See also <a class="reference internal" href="#gevent.pool.Group.imap" title="gevent.pool.Group.imap"><code class="xref py py-meth docutils literal notranslate">imap()</code></a> for more details. </div> </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.join"> join(timeout=None, raise_error=False)<a class="reference internal" href="../_modules/gevent/pool.html#Group.join">[source]</a><a class="headerlink" href="#gevent.pool.Group.join" title="Link to this definition">¶</a></dt> <dd>Wait for this group to become empty at least once. If there are no greenlets in the group, returns immediately. <div class="admonition note"> Note By the time the waiting code (the caller of this method) regains control, a greenlet may have been added to this group, and so this object may no longer be empty. (That is, <code class="docutils literal notranslate">group.join(); assert len(group) == 0</code> is not guaranteed to hold.) This method only guarantees that the group reached a <code class="docutils literal notranslate">len</code> of 0 at some point. </div> <dl class="field-list simple"> <dt class="field-odd">Parameters:</dt> <dd class="field-odd">raise_error (<a class="reference external" href="https://docs.python.org/3/library/functions.html#bool" title="(in Python v3.13)">bool</a>) – If True (not the default), if any greenlet that finished while the join was in progress raised an exception, that exception will be raised to the caller of this method. If multiple greenlets raised exceptions, which one gets re-raised is not determined. Only greenlets currently in the group when this method is called are guaranteed to be checked for exceptions. </dd> <dt class="field-even">Return bool:</dt> <dd class="field-even">A value indicating whether this group became empty. If the timeout is specified and the group did not become empty during that timeout, then this will be a false value. Otherwise it will be a true value. </dd> </dl> <div class="versionchanged"> Changed in version 1.2a1: Add the return value. </div> </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.kill"> kill(exception=<class 'greenlet.GreenletExit'>, block=True, timeout=None)<a class="reference internal" href="../_modules/gevent/pool.html#Group.kill">[source]</a><a class="headerlink" href="#gevent.pool.Group.kill" title="Link to this definition">¶</a></dt> <dd>Kill all greenlets being tracked by this group. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.killone"> killone(greenlet, exception=<class 'greenlet.GreenletExit'>, block=True, timeout=None)<a class="reference internal" href="../_modules/gevent/pool.html#Group.killone">[source]</a><a class="headerlink" href="#gevent.pool.Group.killone" title="Link to this definition">¶</a></dt> <dd>If the given greenlet is running and being tracked by this group, kill it. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.map"> map(func, iterable)<a class="headerlink" href="#gevent.pool.Group.map" title="Link to this definition">¶</a></dt> <dd>Return a list made by applying the func to each element of the iterable. <div class="admonition seealso"> See also <a class="reference internal" href="#gevent.pool.Group.imap" title="gevent.pool.Group.imap"><code class="xref py py-meth docutils literal notranslate">imap()</code></a> </div> </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.map_async"> map_async(func, iterable, callback=None)<a class="headerlink" href="#gevent.pool.Group.map_async" title="Link to this definition">¶</a></dt> <dd>A variant of the map() method which returns a Greenlet object that is executing the map function. If callback is specified then it should be a callable which accepts a single argument. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.spawn"> spawn(*args, **kwargs)<a class="reference internal" href="../_modules/gevent/pool.html#Group.spawn">[source]</a><a class="headerlink" href="#gevent.pool.Group.spawn" title="Link to this definition">¶</a></dt> <dd>Begin a new greenlet with the given arguments (which are passed to the greenlet constructor) and add it to the collection of greenlets this group is monitoring. <dl class="field-list simple"> <dt class="field-odd">Returns:</dt> <dd class="field-odd">The newly started greenlet. </dd> </dl> </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.start"> start(greenlet)<a class="reference internal" href="../_modules/gevent/pool.html#Group.start">[source]</a><a class="headerlink" href="#gevent.pool.Group.start" title="Link to this definition">¶</a></dt> <dd>Add the unstarted greenlet to the collection of greenlets this group is monitoring, and then start it. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Group.wait_available"> wait_available(timeout=None)<a class="reference internal" href="../_modules/gevent/pool.html#Group.wait_available">[source]</a><a class="headerlink" href="#gevent.pool.Group.wait_available" title="Link to this definition">¶</a></dt> <dd>Block until it is possible to <a class="reference internal" href="#gevent.pool.Group.spawn" title="gevent.pool.Group.spawn"><code class="xref py py-meth docutils literal notranslate">spawn()</code></a> a new greenlet. In this implementation, because there are no limits on the number of tracked greenlets, this will always return immediately. </dd></dl> </dd></dl> <dl class="py class"> <dt class="sig sig-object py" id="gevent.pool.PoolFull"> class PoolFull<a class="reference internal" href="../_modules/gevent/pool.html#PoolFull">[source]</a><a class="headerlink" href="#gevent.pool.PoolFull" title="Link to this definition">¶</a></dt> <dd>Bases: <a class="reference internal" href="gevent.queue.html#gevent.queue.Full" title="queue.Full"><code class="xref py py-class docutils literal notranslate">Full</code></a> Raised when a Pool is full and an attempt was made to add a new greenlet to it in non-blocking mode. </dd></dl> <dl class="py class"> <dt class="sig sig-object py" id="gevent.pool.Pool"> class Pool(size=None, greenlet_class=None)<a class="reference internal" href="../_modules/gevent/pool.html#Pool">[source]</a><a class="headerlink" href="#gevent.pool.Pool" title="Link to this definition">¶</a></dt> <dd>Bases: <a class="reference internal" href="#gevent.pool.Group" title="gevent.pool.Group"><code class="xref py py-class docutils literal notranslate">Group</code></a> Create a new pool. A pool is like a group, but the maximum number of members is governed by the size parameter. <dl class="field-list simple"> <dt class="field-odd">Parameters:</dt> <dd class="field-odd">size (<a class="reference external" href="https://docs.python.org/3/library/functions.html#int" title="(in Python v3.13)">int</a>) – If given, this non-negative integer is the maximum count of active greenlets that will be allowed in this pool. A few values have special significance: <ul class="simple"> <li><a class="reference external" href="https://docs.python.org/3/library/constants.html#None" title="(in Python v3.13)"><code class="xref py py-obj docutils literal notranslate">None</code></a> (the default) places no limit on the number of greenlets. This is useful when you want to track, but not limit, greenlets. In general, a <a class="reference internal" href="#gevent.pool.Group" title="gevent.pool.Group"><code class="xref py py-class docutils literal notranslate">Group</code></a> may be a more efficient way to achieve the same effect, but some things need the additional abilities of this class (one example being the spawn parameter of <a class="reference internal" href="gevent.baseserver.html#gevent.baseserver.BaseServer" title="gevent.baseserver.BaseServer"><code class="xref py py-class docutils literal notranslate">gevent.baseserver.BaseServer</code></a> and its subclass <a class="reference internal" href="gevent.pywsgi.html#gevent.pywsgi.WSGIServer" title="gevent.pywsgi.WSGIServer"><code class="xref py py-class docutils literal notranslate">gevent.pywsgi.WSGIServer</code></a>).</li> <li><code class="docutils literal notranslate">0</code> creates a pool that can never have any active greenlets. Attempting to spawn in this pool will block forever. This is only useful if an application uses <a class="reference internal" href="#gevent.pool.Pool.wait_available" title="gevent.pool.Pool.wait_available"><code class="xref py py-meth docutils literal notranslate">wait_available()</code></a> with a timeout and checks <a class="reference internal" href="#gevent.pool.Pool.free_count" title="gevent.pool.Pool.free_count"><code class="xref py py-meth docutils literal notranslate">free_count()</code></a> before attempting to spawn.</li> </ul> </dd> </dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Pool.add"> add(greenlet, blocking=True, timeout=None)<a class="reference internal" href="../_modules/gevent/pool.html#Pool.add">[source]</a><a class="headerlink" href="#gevent.pool.Pool.add" title="Link to this definition">¶</a></dt> <dd>Begin tracking the given unstarted greenlet, possibly blocking until space is available. Usually you should call <a class="reference internal" href="#gevent.pool.Pool.start" title="gevent.pool.Pool.start"><code class="xref py py-meth docutils literal notranslate">start()</code></a> to track and start the greenlet instead of using this lower-level method, or <code class="xref py py-meth docutils literal notranslate">spawn()</code> to also create the greenlet. <dl class="field-list simple"> <dt class="field-odd">Parameters:</dt> <dd class="field-odd"><ul class="simple"> <li>blocking (<a class="reference external" href="https://docs.python.org/3/library/functions.html#bool" title="(in Python v3.13)">bool</a>) – If True (the default), this function will block until the pool has space or a timeout occurs. If False, this function will immediately raise a Timeout if the pool is currently full.</li> <li>timeout (<a class="reference external" href="https://docs.python.org/3/library/functions.html#float" title="(in Python v3.13)">float</a>) – The maximum number of seconds this method will block, if <code class="docutils literal notranslate">blocking</code> is True. (Ignored if <code class="docutils literal notranslate">blocking</code> is False.)</li> </ul> </dd> <dt class="field-even">Raises:</dt> <dd class="field-even"><a class="reference internal" href="#gevent.pool.PoolFull" title="gevent.pool.PoolFull">PoolFull</a> – if either <code class="docutils literal notranslate">blocking</code> is False and the pool was full, or if <code class="docutils literal notranslate">blocking</code> is True and <code class="docutils literal notranslate">timeout</code> was exceeded. </dd> </dl> <div class="admonition caution"> Caution If the greenlet has already been started and blocking is true, then the greenlet may run to completion while the current greenlet blocks waiting to track it. This would enable higher concurrency than desired. </div> <div class="admonition seealso"> See also <a class="reference internal" href="#gevent.pool.Group.add" title="gevent.pool.Group.add"><code class="xref py py-meth docutils literal notranslate">Group.add()</code></a> </div> <div class="versionchanged"> Changed in version 1.3.0: Added the <code class="docutils literal notranslate">blocking</code> and <code class="docutils literal notranslate">timeout</code> parameters. </div> </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Pool.free_count"> free_count()<a class="reference internal" href="../_modules/gevent/pool.html#Pool.free_count">[source]</a><a class="headerlink" href="#gevent.pool.Pool.free_count" title="Link to this definition">¶</a></dt> <dd>Return a number indicating approximately how many more members can be added to this pool. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Pool.full"> full()<a class="reference internal" href="../_modules/gevent/pool.html#Pool.full">[source]</a><a class="headerlink" href="#gevent.pool.Pool.full" title="Link to this definition">¶</a></dt> <dd>Return a boolean indicating whether this pool is full, e.g. if <a class="reference internal" href="#gevent.pool.Pool.add" title="gevent.pool.Pool.add"><code class="xref py py-meth docutils literal notranslate">add()</code></a> would block. <dl class="field-list simple"> <dt class="field-odd">Returns:</dt> <dd class="field-odd">False if there is room for new members, True if there isn’t. </dd> </dl> </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Pool.start"> start(greenlet, blocking=True, timeout=None) → <a class="reference external" href="https://docs.python.org/3/library/constants.html#None" title="(in Python v3.13)">None</a><a class="reference internal" href="../_modules/gevent/pool.html#Pool.start">[source]</a><a class="headerlink" href="#gevent.pool.Pool.start" title="Link to this definition">¶</a></dt> <dd>Add the unstarted greenlet to the collection of greenlets this group is monitoring and then start it. Parameters are as for <a class="reference internal" href="#gevent.pool.Pool.add" title="gevent.pool.Pool.add"><code class="xref py py-meth docutils literal notranslate">add()</code></a>. </dd></dl> <dl class="py method"> <dt class="sig sig-object py" id="gevent.pool.Pool.wait_available"> wait_available(timeout=None)<a class="reference internal" href="../_modules/gevent/pool.html#Pool.wait_available">[source]</a><a class="headerlink" href="#gevent.pool.Pool.wait_available" title="Link to this definition">¶</a></dt> <dd>Wait until it’s possible to spawn a greenlet in this pool. <dl class="field-list simple"> <dt class="field-odd">Parameters:</dt> <dd class="field-odd">timeout (<a class="reference external" href="https://docs.python.org/3/library/functions.html#float" title="(in Python v3.13)">float</a>) – If given, only wait the specified number of seconds. </dd> </dl> <div class="admonition warning"> Warning If the pool was initialized with a size of 0, this method will block forever unless a timeout is given. </div> <dl class="field-list simple"> <dt class="field-odd">Returns:</dt> <dd class="field-odd">A number indicating how many new greenlets can be put into the pool without blocking. </dd> </dl> <div class="versionchanged"> Changed in version 1.1a3: Added the <code class="docutils literal notranslate">timeout</code> parameter. </div> </dd></dl> </dd></dl> </section> </article> </div> <footer> <div class="related-pages"> <a class="next-page" href="gevent.pywsgi.html"> <div class="page-info"> <div class="context"> Next </div> <div class="title"><code class="xref py py-mod docutils literal notranslate">gevent.pywsgi</code> – A pure-Python, gevent-friendly WSGI server</div> </div> <svg class="furo-related-icon"><use href="#svg-arrow-right"></use></svg> </a> <a class="prev-page" href="gevent.os.html"> <svg class="furo-related-icon"><use href="#svg-arrow-right"></use></svg> <div class="page-info"> <div class="context"> Previous </div> <div class="title"><code class="xref py py-mod docutils literal notranslate">gevent.os</code> – Low-level operating system functions from <code class="xref py py-mod docutils literal notranslate">os</code></div> </div> </a> </div> <div class="bottom-of-page"> <div class="left-details"> <div class="copyright"> Copyright © 2009-2023, gevent contributors </div> Made with <a href="https://www.sphinx-doc.org/">Sphinx</a> and <a class="muted-link" href="https://pradyunsg.me">@pradyunsg</a>'s <a href="https://github.com/pradyunsg/furo">Furo</a> </div> <div class="right-details"> </div> </div> </footer> </div> <aside class="toc-drawer"> <div class="toc-sticky toc-scroll"> <div class="toc-title-container"> On this page </div> <div class="toc-tree-container"> <div class="toc-tree"> <ul> <li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate">gevent.pool</code> – Managing greenlets in a group</a><ul> <li><a class="reference internal" href="#gevent.pool.Group"><code class="docutils literal notranslate">Group</code></a><ul> <li><a class="reference internal" href="#gevent.pool.Group.greenlet_class"><code class="docutils literal notranslate">Group.greenlet_class</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.__len__"><code class="docutils literal notranslate">Group.__len__()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.__contains__"><code class="docutils literal notranslate">Group.__contains__()</code></a></li> <li><a class="reference internal" href="#id0"><code class="docutils literal notranslate">Group.greenlet_class</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.add"><code class="docutils literal notranslate">Group.add()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.apply"><code class="docutils literal notranslate">Group.apply()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.apply_async"><code class="docutils literal notranslate">Group.apply_async()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.apply_cb"><code class="docutils literal notranslate">Group.apply_cb()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.discard"><code class="docutils literal notranslate">Group.discard()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.full"><code class="docutils literal notranslate">Group.full()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.imap"><code class="docutils literal notranslate">Group.imap()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.imap_unordered"><code class="docutils literal notranslate">Group.imap_unordered()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.join"><code class="docutils literal notranslate">Group.join()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.kill"><code class="docutils literal notranslate">Group.kill()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.killone"><code class="docutils literal notranslate">Group.killone()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.map"><code class="docutils literal notranslate">Group.map()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.map_async"><code class="docutils literal notranslate">Group.map_async()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.spawn"><code class="docutils literal notranslate">Group.spawn()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.start"><code class="docutils literal notranslate">Group.start()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Group.wait_available"><code class="docutils literal notranslate">Group.wait_available()</code></a></li> </ul> </li> <li><a class="reference internal" href="#gevent.pool.PoolFull"><code class="docutils literal notranslate">PoolFull</code></a></li> <li><a class="reference internal" href="#gevent.pool.Pool"><code class="docutils literal notranslate">Pool</code></a><ul> <li><a class="reference internal" href="#gevent.pool.Pool.add"><code class="docutils literal notranslate">Pool.add()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Pool.free_count"><code class="docutils literal notranslate">Pool.free_count()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Pool.full"><code class="docutils literal notranslate">Pool.full()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Pool.start"><code class="docutils literal notranslate">Pool.start()</code></a></li> <li><a class="reference internal" href="#gevent.pool.Pool.wait_available"><code class="docutils literal notranslate">Pool.wait_available()</code></a></li> </ul> </li> </ul> </li> </ul> </div> </div> </div> </aside> </div> 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