* **Iterators returned by the [iter()](#iterator) function, such as list\_iterator and set\_iterator.**

* **Objects returned by the [itertools](#itertools) module, such as count, repeat and cycle.**

* **File objects returned by the [open()](#open) function, etc.**

<div><h4 id="pythonhasmanydifferentiteratorobjects">Python has many different iterator objects:</h4><ul>

<li><strong>Iterators returned by the <a href="#iterator">iter()</a> function, such as list_iterator and set_iterator.</strong></li>

<li><strong>Objects returned by the <a href="#itertools">itertools</a> module, such as count, repeat and cycle.</strong></li>

<li><strong>File objects returned by the <a href="#open">open()</a> function, etc.</strong></li>

</ul><div><h3 id="callable">Callable</h3><ul>

<li><strong>All functions and classes have a call() method, hence are callable.</strong></li>

<strong>combinatorics, <a href="#combinatorics">8</a></strong><br>

<strong>command line arguments, <a href="#commandlinearguments">22</a></strong><br>

<strong>comparable, <a href="#comparable">16</a></strong><br>

<strong>context manager, <a href="#contextmanager">17</a></strong><br>

<strong>copy function, <a href="#copy">15</a></strong><br>

<strong>coroutine, <a href="#coroutines">33</a></strong><br>

<strong>functools module, <a href="#mapfilterreduce">11</a>, <a href="#partial">12</a>, <a href="#decorator">13</a>, <a href="#sortable">16</a></strong><br>

<strong>futures, <a href="#threadpool">30</a></strong> </p>

<h3 id="g">G</h3>

<strong>global keyword, <a href="#nonlocal">12</a></strong></p>

<h3 id="h">H</h3>

<p><strong>hashable, <a href="#hashable">16</a></strong><br>

<p><strong>json module, <a href="#json">25</a>, <a href="#encodedecode">46</a></strong> </p>

<h3 id="l">L</h3>

<p><strong>lambda, <a href="#lambda">11</a></strong><br>

<strong>lists, <a href="#list">1</a>-<a href="#list">2</a>, <a href="#otheruses">11</a></strong><br>

<strong>locks, <a href="#lock">29</a></strong><br>

<strong>logging, <a href="#logging">35</a></strong> </p>

<strong>combinatorics, 8</strong><br>

<strong>command line arguments, 22</strong><br>

<strong>comparable, 16</strong><br>

<strong>context manager, 17</strong><br>

<strong>copy function, 15</strong><br>

<strong>coroutine, 33</strong><br>