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<!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>23.2. shlex — Simple lexical analysis — Python 2.7.18 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/language_data.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 2.7.18 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="24. 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You should install the python3 and python3-doc packages and read the <a href="file:///usr/share/doc/python3-doc/html/library/shlex.html"> Python documentation for the Python3 version packaged in this release</a>. </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" 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="tk.html" title="24. 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Program Frameworks</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="module-shlex"> <span id="shlex-simple-lexical-analysis"></span><h1>23.2. <a class="reference internal" href="#module-shlex" title="shlex: Simple lexical analysis for Unix shell-like languages."><code class="xref py py-mod docutils literal notranslate"><span class="pre">shlex</span></code></a> — Simple lexical analysis<a class="headerlink" href="#module-shlex" title="Permalink to this headline">¶</a></h1> <div class="versionadded"> <p><span class="versionmodified">New in version 1.5.2.</span></p> </div> <p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/2.7/Lib/shlex.py">Lib/shlex.py</a></p> <hr class="docutils" /> <p>The <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> class makes it easy to write lexical analyzers for simple syntaxes resembling that of the Unix shell. This will often be useful for writing minilanguages, (for example, in run control files for Python applications) or for parsing quoted strings.</p> <p>Prior to Python 2.7.3, this module did not support Unicode input.</p> <p>The <a class="reference internal" href="#module-shlex" title="shlex: Simple lexical analysis for Unix shell-like languages."><code class="xref py py-mod docutils literal notranslate"><span class="pre">shlex</span></code></a> module defines the following functions:</p> <dl class="function"> <dt id="shlex.split"> <code class="descclassname">shlex.</code><code class="descname">split</code><span class="sig-paren">(</span><em>s</em><span class="optional">[</span>, <em>comments</em><span class="optional">[</span>, <em>posix</em><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#shlex.split" title="Permalink to this definition">¶</a></dt> <dd><p>Split the string <em>s</em> using shell-like syntax. If <em>comments</em> is <a class="reference internal" href="constants.html#False" title="False"><code class="xref py py-const docutils literal notranslate"><span class="pre">False</span></code></a> (the default), the parsing of comments in the given string will be disabled (setting the <a class="reference internal" href="#shlex.shlex.commenters" title="shlex.shlex.commenters"><code class="xref py py-attr docutils literal notranslate"><span class="pre">commenters</span></code></a> attribute of the <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> instance to the empty string). This function operates in POSIX mode by default, but uses non-POSIX mode if the <em>posix</em> argument is false.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.3.</span></p> </div> <div class="versionchanged"> <p><span class="versionmodified">Changed in version 2.6: </span>Added the <em>posix</em> parameter.</p> </div> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">Since the <a class="reference internal" href="#shlex.split" title="shlex.split"><code class="xref py py-func docutils literal notranslate"><span class="pre">split()</span></code></a> function instantiates a <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> instance, passing <code class="docutils literal notranslate"><span class="pre">None</span></code> for <em>s</em> will read the string to split from standard input.</p> </div> </dd></dl> <p>The <a class="reference internal" href="#module-shlex" title="shlex: Simple lexical analysis for Unix shell-like languages."><code class="xref py py-mod docutils literal notranslate"><span class="pre">shlex</span></code></a> module defines the following class:</p> <dl class="class"> <dt id="shlex.shlex"> <em class="property">class </em><code class="descclassname">shlex.</code><code class="descname">shlex</code><span class="sig-paren">(</span><span class="optional">[</span><em>instream</em><span class="optional">[</span>, <em>infile</em><span class="optional">[</span>, <em>posix</em><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#shlex.shlex" title="Permalink to this definition">¶</a></dt> <dd><p>A <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> instance or subclass instance is a lexical analyzer object. The initialization argument, if present, specifies where to read characters from. It must be a file-/stream-like object with <a class="reference internal" href="io.html#io.TextIOBase.read" title="io.TextIOBase.read"><code class="xref py py-meth docutils literal notranslate"><span class="pre">read()</span></code></a> and <a class="reference internal" href="io.html#io.TextIOBase.readline" title="io.TextIOBase.readline"><code class="xref py py-meth docutils literal notranslate"><span class="pre">readline()</span></code></a> methods, or a string (strings are accepted since Python 2.3). If no argument is given, input will be taken from <code class="docutils literal notranslate"><span class="pre">sys.stdin</span></code>. The second optional argument is a filename string, which sets the initial value of the <a class="reference internal" href="#shlex.shlex.infile" title="shlex.shlex.infile"><code class="xref py py-attr docutils literal notranslate"><span class="pre">infile</span></code></a> attribute. If the <em>instream</em> argument is omitted or equal to <code class="docutils literal notranslate"><span class="pre">sys.stdin</span></code>, this second argument defaults to “stdin”. The <em>posix</em> argument was introduced in Python 2.3, and defines the operational mode. When <em>posix</em> is not true (default), the <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> instance will operate in compatibility mode. When operating in POSIX mode, <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> will try to be as close as possible to the POSIX shell parsing rules.</p> </dd></dl> <div class="admonition seealso"> <p class="first admonition-title">See also</p> <dl class="last docutils"> <dt>Module <a class="reference internal" href="configparser.html#module-ConfigParser" title="ConfigParser: Configuration file parser."><code class="xref py py-mod docutils literal notranslate"><span class="pre">ConfigParser</span></code></a></dt> <dd>Parser for configuration files similar to the Windows <code class="file docutils literal notranslate"><span class="pre">.ini</span></code> files.</dd> </dl> </div> <div class="section" id="shlex-objects"> <span id="id1"></span><h2>23.2.1. shlex Objects<a class="headerlink" href="#shlex-objects" title="Permalink to this headline">¶</a></h2> <p>A <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> instance has the following methods:</p> <dl class="method"> <dt id="shlex.shlex.get_token"> <code class="descclassname">shlex.</code><code class="descname">get_token</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#shlex.shlex.get_token" title="Permalink to this definition">¶</a></dt> <dd><p>Return a token. If tokens have been stacked using <a class="reference internal" href="#shlex.shlex.push_token" title="shlex.shlex.push_token"><code class="xref py py-meth docutils literal notranslate"><span class="pre">push_token()</span></code></a>, pop a token off the stack. Otherwise, read one from the input stream. If reading encounters an immediate end-of-file, <a class="reference internal" href="#shlex.shlex.eof" title="shlex.shlex.eof"><code class="xref py py-attr docutils literal notranslate"><span class="pre">eof</span></code></a> is returned (the empty string (<code class="docutils literal notranslate"><span class="pre">''</span></code>) in non-POSIX mode, and <code class="docutils literal notranslate"><span class="pre">None</span></code> in POSIX mode).</p> </dd></dl> <dl class="method"> <dt id="shlex.shlex.push_token"> <code class="descclassname">shlex.</code><code class="descname">push_token</code><span class="sig-paren">(</span><em>str</em><span class="sig-paren">)</span><a class="headerlink" href="#shlex.shlex.push_token" title="Permalink to this definition">¶</a></dt> <dd><p>Push the argument onto the token stack.</p> </dd></dl> <dl class="method"> <dt id="shlex.shlex.read_token"> <code class="descclassname">shlex.</code><code class="descname">read_token</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#shlex.shlex.read_token" title="Permalink to this definition">¶</a></dt> <dd><p>Read a raw token. Ignore the pushback stack, and do not interpret source requests. (This is not ordinarily a useful entry point, and is documented here only for the sake of completeness.)</p> </dd></dl> <dl class="method"> <dt id="shlex.shlex.sourcehook"> <code class="descclassname">shlex.</code><code class="descname">sourcehook</code><span class="sig-paren">(</span><em>filename</em><span class="sig-paren">)</span><a class="headerlink" href="#shlex.shlex.sourcehook" title="Permalink to this definition">¶</a></dt> <dd><p>When <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> detects a source request (see <a class="reference internal" href="#shlex.shlex.source" title="shlex.shlex.source"><code class="xref py py-attr docutils literal notranslate"><span class="pre">source</span></code></a> below) this method is given the following token as argument, and expected to return a tuple consisting of a filename and an open file-like object.</p> <p>Normally, this method first strips any quotes off the argument. If the result is an absolute pathname, or there was no previous source request in effect, or the previous source was a stream (such as <code class="docutils literal notranslate"><span class="pre">sys.stdin</span></code>), the result is left alone. Otherwise, if the result is a relative pathname, the directory part of the name of the file immediately before it on the source inclusion stack is prepended (this behavior is like the way the C preprocessor handles <code class="docutils literal notranslate"><span class="pre">#include</span> <span class="pre">"file.h"</span></code>).</p> <p>The result of the manipulations is treated as a filename, and returned as the first component of the tuple, with <a class="reference internal" href="functions.html#open" title="open"><code class="xref py py-func docutils literal notranslate"><span class="pre">open()</span></code></a> called on it to yield the second component. (Note: this is the reverse of the order of arguments in instance initialization!)</p> <p>This hook is exposed so that you can use it to implement directory search paths, addition of file extensions, and other namespace hacks. There is no corresponding ‘close’ hook, but a shlex instance will call the <a class="reference internal" href="io.html#io.IOBase.close" title="io.IOBase.close"><code class="xref py py-meth docutils literal notranslate"><span class="pre">close()</span></code></a> method of the sourced input stream when it returns EOF.</p> <p>For more explicit control of source stacking, use the <a class="reference internal" href="#shlex.shlex.push_source" title="shlex.shlex.push_source"><code class="xref py py-meth docutils literal notranslate"><span class="pre">push_source()</span></code></a> and <a class="reference internal" href="#shlex.shlex.pop_source" title="shlex.shlex.pop_source"><code class="xref py py-meth docutils literal notranslate"><span class="pre">pop_source()</span></code></a> methods.</p> </dd></dl> <dl class="method"> <dt id="shlex.shlex.push_source"> <code class="descclassname">shlex.</code><code class="descname">push_source</code><span class="sig-paren">(</span><em>stream</em><span class="optional">[</span>, <em>filename</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#shlex.shlex.push_source" title="Permalink to this definition">¶</a></dt> <dd><p>Push an input source stream onto the input stack. If the filename argument is specified it will later be available for use in error messages. This is the same method used internally by the <a class="reference internal" href="#shlex.shlex.sourcehook" title="shlex.shlex.sourcehook"><code class="xref py py-meth docutils literal notranslate"><span class="pre">sourcehook()</span></code></a> method.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.1.</span></p> </div> </dd></dl> <dl class="method"> <dt id="shlex.shlex.pop_source"> <code class="descclassname">shlex.</code><code class="descname">pop_source</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#shlex.shlex.pop_source" title="Permalink to this definition">¶</a></dt> <dd><p>Pop the last-pushed input source from the input stack. This is the same method used internally when the lexer reaches EOF on a stacked input stream.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.1.</span></p> </div> </dd></dl> <dl class="method"> <dt id="shlex.shlex.error_leader"> <code class="descclassname">shlex.</code><code class="descname">error_leader</code><span class="sig-paren">(</span><span class="optional">[</span><em>file</em><span class="optional">[</span>, <em>line</em><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#shlex.shlex.error_leader" title="Permalink to this definition">¶</a></dt> <dd><p>This method generates an error message leader in the format of a Unix C compiler error label; the format is <code class="docutils literal notranslate"><span class="pre">'"%s",</span> <span class="pre">line</span> <span class="pre">%d:</span> <span class="pre">'</span></code>, where the <code class="docutils literal notranslate"><span class="pre">%s</span></code> is replaced with the name of the current source file and the <code class="docutils literal notranslate"><span class="pre">%d</span></code> with the current input line number (the optional arguments can be used to override these).</p> <p>This convenience is provided to encourage <a class="reference internal" href="#module-shlex" title="shlex: Simple lexical analysis for Unix shell-like languages."><code class="xref py py-mod docutils literal notranslate"><span class="pre">shlex</span></code></a> users to generate error messages in the standard, parseable format understood by Emacs and other Unix tools.</p> </dd></dl> <p>Instances of <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> subclasses have some public instance variables which either control lexical analysis or can be used for debugging:</p> <dl class="attribute"> <dt id="shlex.shlex.commenters"> <code class="descclassname">shlex.</code><code class="descname">commenters</code><a class="headerlink" href="#shlex.shlex.commenters" title="Permalink to this definition">¶</a></dt> <dd><p>The string of characters that are recognized as comment beginners. All characters from the comment beginner to end of line are ignored. Includes just <code class="docutils literal notranslate"><span class="pre">'#'</span></code> by default.</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.wordchars"> <code class="descclassname">shlex.</code><code class="descname">wordchars</code><a class="headerlink" href="#shlex.shlex.wordchars" title="Permalink to this definition">¶</a></dt> <dd><p>The string of characters that will accumulate into multi-character tokens. By default, includes all ASCII alphanumerics and underscore.</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.whitespace"> <code class="descclassname">shlex.</code><code class="descname">whitespace</code><a class="headerlink" href="#shlex.shlex.whitespace" title="Permalink to this definition">¶</a></dt> <dd><p>Characters that will be considered whitespace and skipped. Whitespace bounds tokens. By default, includes space, tab, linefeed and carriage-return.</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.escape"> <code class="descclassname">shlex.</code><code class="descname">escape</code><a class="headerlink" href="#shlex.shlex.escape" title="Permalink to this definition">¶</a></dt> <dd><p>Characters that will be considered as escape. This will be only used in POSIX mode, and includes just <code class="docutils literal notranslate"><span class="pre">'\'</span></code> by default.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.3.</span></p> </div> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.quotes"> <code class="descclassname">shlex.</code><code class="descname">quotes</code><a class="headerlink" href="#shlex.shlex.quotes" title="Permalink to this definition">¶</a></dt> <dd><p>Characters that will be considered string quotes. The token accumulates until the same quote is encountered again (thus, different quote types protect each other as in the shell.) By default, includes ASCII single and double quotes.</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.escapedquotes"> <code class="descclassname">shlex.</code><code class="descname">escapedquotes</code><a class="headerlink" href="#shlex.shlex.escapedquotes" title="Permalink to this definition">¶</a></dt> <dd><p>Characters in <a class="reference internal" href="#shlex.shlex.quotes" title="shlex.shlex.quotes"><code class="xref py py-attr docutils literal notranslate"><span class="pre">quotes</span></code></a> that will interpret escape characters defined in <a class="reference internal" href="#shlex.shlex.escape" title="shlex.shlex.escape"><code class="xref py py-attr docutils literal notranslate"><span class="pre">escape</span></code></a>. This is only used in POSIX mode, and includes just <code class="docutils literal notranslate"><span class="pre">'"'</span></code> by default.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.3.</span></p> </div> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.whitespace_split"> <code class="descclassname">shlex.</code><code class="descname">whitespace_split</code><a class="headerlink" href="#shlex.shlex.whitespace_split" title="Permalink to this definition">¶</a></dt> <dd><p>If <code class="docutils literal notranslate"><span class="pre">True</span></code>, tokens will only be split in whitespaces. This is useful, for example, for parsing command lines with <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a>, getting tokens in a similar way to shell arguments.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.3.</span></p> </div> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.infile"> <code class="descclassname">shlex.</code><code class="descname">infile</code><a class="headerlink" href="#shlex.shlex.infile" title="Permalink to this definition">¶</a></dt> <dd><p>The name of the current input file, as initially set at class instantiation time or stacked by later source requests. It may be useful to examine this when constructing error messages.</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.instream"> <code class="descclassname">shlex.</code><code class="descname">instream</code><a class="headerlink" href="#shlex.shlex.instream" title="Permalink to this definition">¶</a></dt> <dd><p>The input stream from which this <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> instance is reading characters.</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.source"> <code class="descclassname">shlex.</code><code class="descname">source</code><a class="headerlink" href="#shlex.shlex.source" title="Permalink to this definition">¶</a></dt> <dd><p>This attribute is <code class="docutils literal notranslate"><span class="pre">None</span></code> by default. If you assign a string to it, that string will be recognized as a lexical-level inclusion request similar to the <code class="docutils literal notranslate"><span class="pre">source</span></code> keyword in various shells. That is, the immediately following token will be opened as a filename and input will be taken from that stream until EOF, at which point the <a class="reference internal" href="io.html#io.IOBase.close" title="io.IOBase.close"><code class="xref py py-meth docutils literal notranslate"><span class="pre">close()</span></code></a> method of that stream will be called and the input source will again become the original input stream. Source requests may be stacked any number of levels deep.</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.debug"> <code class="descclassname">shlex.</code><code class="descname">debug</code><a class="headerlink" href="#shlex.shlex.debug" title="Permalink to this definition">¶</a></dt> <dd><p>If this attribute is numeric and <code class="docutils literal notranslate"><span class="pre">1</span></code> or more, a <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> instance will print verbose progress output on its behavior. If you need to use this, you can read the module source code to learn the details.</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.lineno"> <code class="descclassname">shlex.</code><code class="descname">lineno</code><a class="headerlink" href="#shlex.shlex.lineno" title="Permalink to this definition">¶</a></dt> <dd><p>Source line number (count of newlines seen so far plus one).</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.token"> <code class="descclassname">shlex.</code><code class="descname">token</code><a class="headerlink" href="#shlex.shlex.token" title="Permalink to this definition">¶</a></dt> <dd><p>The token buffer. It may be useful to examine this when catching exceptions.</p> </dd></dl> <dl class="attribute"> <dt id="shlex.shlex.eof"> <code class="descclassname">shlex.</code><code class="descname">eof</code><a class="headerlink" href="#shlex.shlex.eof" title="Permalink to this definition">¶</a></dt> <dd><p>Token used to determine end of file. This will be set to the empty string (<code class="docutils literal notranslate"><span class="pre">''</span></code>), in non-POSIX mode, and to <code class="docutils literal notranslate"><span class="pre">None</span></code> in POSIX mode.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.3.</span></p> </div> </dd></dl> </div> <div class="section" id="parsing-rules"> <span id="shlex-parsing-rules"></span><h2>23.2.2. Parsing Rules<a class="headerlink" href="#parsing-rules" title="Permalink to this headline">¶</a></h2> <p>When operating in non-POSIX mode, <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> will try to obey to the following rules.</p> <ul class="simple"> <li>Quote characters are not recognized within words (<code class="docutils literal notranslate"><span class="pre">Do"Not"Separate</span></code> is parsed as the single word <code class="docutils literal notranslate"><span class="pre">Do"Not"Separate</span></code>);</li> <li>Escape characters are not recognized;</li> <li>Enclosing characters in quotes preserve the literal value of all characters within the quotes;</li> <li>Closing quotes separate words (<code class="docutils literal notranslate"><span class="pre">"Do"Separate</span></code> is parsed as <code class="docutils literal notranslate"><span class="pre">"Do"</span></code> and <code class="docutils literal notranslate"><span class="pre">Separate</span></code>);</li> <li>If <a class="reference internal" href="#shlex.shlex.whitespace_split" title="shlex.shlex.whitespace_split"><code class="xref py py-attr docutils literal notranslate"><span class="pre">whitespace_split</span></code></a> is <code class="docutils literal notranslate"><span class="pre">False</span></code>, any character not declared to be a word character, whitespace, or a quote will be returned as a single-character token. If it is <code class="docutils literal notranslate"><span class="pre">True</span></code>, <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> will only split words in whitespaces;</li> <li>EOF is signaled with an empty string (<code class="docutils literal notranslate"><span class="pre">''</span></code>);</li> <li>It’s not possible to parse empty strings, even if quoted.</li> </ul> <p>When operating in POSIX mode, <a class="reference internal" href="#shlex.shlex" title="shlex.shlex"><code class="xref py py-class docutils literal notranslate"><span class="pre">shlex</span></code></a> will try to obey to the following parsing rules.</p> <ul class="simple"> <li>Quotes are stripped out, and do not separate words (<code class="docutils literal notranslate"><span class="pre">"Do"Not"Separate"</span></code> is parsed as the single word <code class="docutils literal notranslate"><span class="pre">DoNotSeparate</span></code>);</li> <li>Non-quoted escape characters (e.g. <code class="docutils literal notranslate"><span class="pre">'\'</span></code>) preserve the literal value of the next character that follows;</li> <li>Enclosing characters in quotes which are not part of <a class="reference internal" href="#shlex.shlex.escapedquotes" title="shlex.shlex.escapedquotes"><code class="xref py py-attr docutils literal notranslate"><span class="pre">escapedquotes</span></code></a> (e.g. <code class="docutils literal notranslate"><span class="pre">"'"</span></code>) preserve the literal value of all characters within the quotes;</li> <li>Enclosing characters in quotes which are part of <a class="reference internal" href="#shlex.shlex.escapedquotes" title="shlex.shlex.escapedquotes"><code class="xref py py-attr docutils literal notranslate"><span class="pre">escapedquotes</span></code></a> (e.g. <code class="docutils literal notranslate"><span class="pre">'"'</span></code>) preserves the literal value of all characters within the quotes, with the exception of the characters mentioned in <a class="reference internal" href="#shlex.shlex.escape" title="shlex.shlex.escape"><code class="xref py py-attr docutils literal notranslate"><span class="pre">escape</span></code></a>. The escape characters retain its special meaning only when followed by the quote in use, or the escape character itself. Otherwise the escape character will be considered a normal character.</li> <li>EOF is signaled with a <a class="reference internal" href="constants.html#None" title="None"><code class="xref py py-const docutils literal notranslate"><span class="pre">None</span></code></a> value;</li> <li>Quoted empty strings (<code class="docutils literal notranslate"><span class="pre">''</span></code>) are allowed;</li> </ul> </div> </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="#">23.2. <code class="docutils literal notranslate"><span class="pre">shlex</span></code> — Simple lexical analysis</a><ul> <li><a class="reference internal" href="#shlex-objects">23.2.1. shlex Objects</a></li> <li><a class="reference internal" href="#parsing-rules">23.2.2. Parsing Rules</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="cmd.html" title="previous chapter">23.1. <code class="docutils literal notranslate"><span class="pre">cmd</span></code> — Support for line-oriented command interpreters</a></p> <h4>Next topic</h4> <p class="topless"><a href="tk.html" title="next chapter">24. 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