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<title>5.21.2 Parsing Rules</title>
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<H2><A NAME="SECTION0072120000000000000000"></A><A NAME="shlex-parsing-rules"></A>
<BR>
5.21.2 Parsing Rules
</H2>
<P>
When operating in non-POSIX mode, <tt class="class">shlex</tt> will try to obey to
the following rules.
<P>
<UL>
<LI>Quote characters are not recognized within words
(<code>Do"Not"Separate</code> is parsed as the single word
<code>Do"Not"Separate</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>"Do"Separate</code> is parsed
as <code>"Do"</code> and <code>Separate</code>);
</LI>
<LI>If <tt class="member">whitespace_split</tt> is <code>False</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>True</code>,
<tt class="class">shlex</tt> will only split words in whitespaces;
</LI>
<LI>EOF is signaled with an empty string (<code>''</code>);
</LI>
<LI>It's not possible to parse empty strings, even if quoted.
</LI>
</UL>
<P>
When operating in POSIX mode, <tt class="class">shlex</tt> will try to obey to the
following parsing rules.
<P>
<UL>
<LI>Quotes are stripped out, and do not separate words
(<code>"Do"Not"Separate"</code> is parsed as the single word
<code>DoNotSeparate</code>);
</LI>
<LI>Non-quoted escape characters (e.g. "<tt class="character">\</tt>")
preserve the literal value of the next character that follows;
</LI>
<LI>Enclosing characters in quotes which are not part of
<tt class="member">escapedquotes</tt> (e.g. "<tt class="character">'</tt>") preserve the literal
value of all characters within the quotes;
</LI>
<LI>Enclosing characters in quotes which are part of
<tt class="member">escapedquotes</tt> (e.g. "<tt class="character">"</tt>") preserves the literal
value of all characters within the quotes, with the exception of
the characters mentioned in <tt class="member">escape</tt>. 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 <tt class="constant">None</tt> value;
</LI>
<LI>Quoted empty strings (<code>''</code>) are allowed;
</LI>
</UL>
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<span class="release-info">Release 2.4.3, documentation updated on 29 March 2006.</span>
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