D7net
Home
Console
Upload
information
Create File
Create Folder
About
Tools
:
/
usr
/
share
/
doc
/
python2-docs
/
html
/
reference
/
Filename :
index.html
back
Copy
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>The Python Language Reference — Python 2.7.16 documentation</title> <link rel="stylesheet" href="../_static/classic.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 2.7.16 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="1. Introduction" href="introduction.html" /> <link rel="prev" title="4. Using Python on a Macintosh" href="../using/mac.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="https://docs.python.org/2/reference/index.html" /> <script type="text/javascript" src="../_static/copybutton.js"></script> </head><body> <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="introduction.html" title="1. Introduction" accesskey="N">next</a> |</li> <li class="right" > <a href="../using/mac.html" title="4. Using Python on a Macintosh" accesskey="P">previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.16 documentation</a> » </li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="the-python-language-reference"> <span id="reference-index"></span><h1>The Python Language Reference<a class="headerlink" href="#the-python-language-reference" title="Permalink to this headline">¶</a></h1> <p>This reference manual describes the syntax and “core semantics” of the language. It is terse, but attempts to be exact and complete. The semantics of non-essential built-in object types and of the built-in functions and modules are described in <a class="reference internal" href="../library/index.html#library-index"><span class="std std-ref">The Python Standard Library</span></a>. For an informal introduction to the language, see <a class="reference internal" href="../tutorial/index.html#tutorial-index"><span class="std std-ref">The Python Tutorial</span></a>. For C or C++ programmers, two additional manuals exist: <a class="reference internal" href="../extending/index.html#extending-index"><span class="std std-ref">Extending and Embedding the Python Interpreter</span></a> describes the high-level picture of how to write a Python extension module, and the <a class="reference internal" href="../c-api/index.html#c-api-index"><span class="std std-ref">Python/C API Reference Manual</span></a> describes the interfaces available to C/C++ programmers in detail.</p> <div class="toctree-wrapper compound"> <ul> <li class="toctree-l1"><a class="reference internal" href="introduction.html">1. Introduction</a><ul> <li class="toctree-l2"><a class="reference internal" href="introduction.html#alternate-implementations">1.1. Alternate Implementations</a></li> <li class="toctree-l2"><a class="reference internal" href="introduction.html#notation">1.2. Notation</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="lexical_analysis.html">2. Lexical analysis</a><ul> <li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#line-structure">2.1. Line structure</a></li> <li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#other-tokens">2.2. Other tokens</a></li> <li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#identifiers">2.3. Identifiers and keywords</a></li> <li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#literals">2.4. Literals</a></li> <li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#operators">2.5. Operators</a></li> <li class="toctree-l2"><a class="reference internal" href="lexical_analysis.html#delimiters">2.6. Delimiters</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="datamodel.html">3. Data model</a><ul> <li class="toctree-l2"><a class="reference internal" href="datamodel.html#objects-values-and-types">3.1. Objects, values and types</a></li> <li class="toctree-l2"><a class="reference internal" href="datamodel.html#the-standard-type-hierarchy">3.2. The standard type hierarchy</a></li> <li class="toctree-l2"><a class="reference internal" href="datamodel.html#new-style-and-classic-classes">3.3. New-style and classic classes</a></li> <li class="toctree-l2"><a class="reference internal" href="datamodel.html#special-method-names">3.4. Special method names</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="executionmodel.html">4. Execution model</a><ul> <li class="toctree-l2"><a class="reference internal" href="executionmodel.html#naming-and-binding">4.1. Naming and binding</a></li> <li class="toctree-l2"><a class="reference internal" href="executionmodel.html#exceptions">4.2. Exceptions</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="expressions.html">5. Expressions</a><ul> <li class="toctree-l2"><a class="reference internal" href="expressions.html#arithmetic-conversions">5.1. Arithmetic conversions</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#atoms">5.2. Atoms</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#primaries">5.3. Primaries</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#the-power-operator">5.4. The power operator</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#unary-arithmetic-and-bitwise-operations">5.5. Unary arithmetic and bitwise operations</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#binary-arithmetic-operations">5.6. Binary arithmetic operations</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#shifting-operations">5.7. Shifting operations</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#binary-bitwise-operations">5.8. Binary bitwise operations</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#comparisons">5.9. Comparisons</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#boolean-operations">5.10. Boolean operations</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#conditional-expressions">5.11. Conditional Expressions</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#lambda">5.12. Lambdas</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#expression-lists">5.13. Expression lists</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#evaluation-order">5.14. Evaluation order</a></li> <li class="toctree-l2"><a class="reference internal" href="expressions.html#operator-precedence">5.15. Operator precedence</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="simple_stmts.html">6. Simple statements</a><ul> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#expression-statements">6.1. Expression statements</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#assignment-statements">6.2. Assignment statements</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-assert-statement">6.3. The <code class="docutils literal notranslate"><span class="pre">assert</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-pass-statement">6.4. The <code class="docutils literal notranslate"><span class="pre">pass</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-del-statement">6.5. The <code class="docutils literal notranslate"><span class="pre">del</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-print-statement">6.6. The <code class="docutils literal notranslate"><span class="pre">print</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-return-statement">6.7. The <code class="docutils literal notranslate"><span class="pre">return</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-yield-statement">6.8. The <code class="docutils literal notranslate"><span class="pre">yield</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-raise-statement">6.9. The <code class="docutils literal notranslate"><span class="pre">raise</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-break-statement">6.10. The <code class="docutils literal notranslate"><span class="pre">break</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-continue-statement">6.11. The <code class="docutils literal notranslate"><span class="pre">continue</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-import-statement">6.12. The <code class="docutils literal notranslate"><span class="pre">import</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-global-statement">6.13. The <code class="docutils literal notranslate"><span class="pre">global</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="simple_stmts.html#the-exec-statement">6.14. The <code class="docutils literal notranslate"><span class="pre">exec</span></code> statement</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="compound_stmts.html">7. Compound statements</a><ul> <li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-if-statement">7.1. The <code class="docutils literal notranslate"><span class="pre">if</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-while-statement">7.2. The <code class="docutils literal notranslate"><span class="pre">while</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-for-statement">7.3. The <code class="docutils literal notranslate"><span class="pre">for</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-try-statement">7.4. The <code class="docutils literal notranslate"><span class="pre">try</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#the-with-statement">7.5. The <code class="docutils literal notranslate"><span class="pre">with</span></code> statement</a></li> <li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#function-definitions">7.6. Function definitions</a></li> <li class="toctree-l2"><a class="reference internal" href="compound_stmts.html#class-definitions">7.7. Class definitions</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="toplevel_components.html">8. Top-level components</a><ul> <li class="toctree-l2"><a class="reference internal" href="toplevel_components.html#complete-python-programs">8.1. Complete Python programs</a></li> <li class="toctree-l2"><a class="reference internal" href="toplevel_components.html#file-input">8.2. File input</a></li> <li class="toctree-l2"><a class="reference internal" href="toplevel_components.html#interactive-input">8.3. Interactive input</a></li> <li class="toctree-l2"><a class="reference internal" href="toplevel_components.html#expression-input">8.4. Expression input</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="grammar.html">9. Full Grammar specification</a></li> </ul> </div> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h4>Previous topic</h4> <p class="topless"><a href="../using/mac.html" title="previous chapter">4. Using Python on a Macintosh</a></p> <h4>Next topic</h4> <p class="topless"><a href="introduction.html" title="next chapter">1. Introduction</a></p> <div role="note" aria-label="source link"> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../_sources/reference/index.rst.txt" rel="nofollow">Show Source</a></li> </ul> </div> <div id="searchbox" style="display: none" role="search"> <h3>Quick search</h3> <div class="searchformwrapper"> <form class="search" action="../search.html" method="get"> <input 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> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </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="introduction.html" title="1. Introduction" >next</a> |</li> <li class="right" > <a href="../using/mac.html" title="4. Using Python on a Macintosh" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.16 documentation</a> » </li> </ul> </div> <div class="footer"> © <a href="../copyright.html">Copyright</a> 1990-2019, Python Software Foundation. <br /> The Python Software Foundation is a non-profit corporation. <a href="https://www.python.org/psf/donations/">Please donate.</a> <br /> Last updated on Mar 27, 2019. <a href="../bugs.html">Found a bug</a>? <br /> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.7.6. </div> </body> </html>