Unmatched groups are replaced with an empty string.
-.. function:: escape(string)
+.. function:: escape(pattern)
- Escape all the characters in pattern except ASCII letters, numbers and ``'_'``.
+ Escape all the characters in *pattern* except ASCII letters, numbers and ``'_'``.
This is useful if you want to match an arbitrary literal string that may
- have regular expression metacharacters in it.
+ have regular expression metacharacters in it. For example::
+
+ >>> print(re.escape('python.exe'))
+ python\.exe
+
+ >>> legal_chars = string.ascii_lowercase + string.digits + "!#$%&'*+-.^_`|~:"
+ >>> print('[%s]+' % re.escape(legal_chars))
+ [abcdefghijklmnopqrstuvwxyz0123456789\!\#\$\%\&\'\*\+\-\.\^_\`\|\~\:]+
+
+ >>> operators = ['+', '-', '*', '/', '**']
+ >>> print('|'.join(map(re.escape, sorted(operators, reverse=True))))
+ \/|\-|\+|\*\*|\*
.. versionchanged:: 3.3
The ``'_'`` character is no longer escaped.
whatsnew/3.2,,:gz,">>> with tarfile.open(name='myarchive.tar.gz', mode='w:gz') as tf:"
whatsnew/3.2,,:location,zope9-location = ${zope9:location}
whatsnew/3.2,,:prefix,zope-conf = ${custom:prefix}/etc/zope.conf
+library/re,,`,!#$%&'*+-.^_`|~:
+library/re,,`,\!\#\$\%\&\'\*\+\-\.\^_\`\|\~\:
library/tarfile,,:xz,'x:xz'
library/xml.etree.elementtree,,:sometag,prefix:sometag
library/xml.etree.elementtree,,:fictional,"<actors xmlns:fictional=""http://characters.example.com"""