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Diffstat (limited to 'Doc/library/re.rst')
| -rw-r--r-- | Doc/library/re.rst | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/Doc/library/re.rst b/Doc/library/re.rst index 26f2a3824e..b0cb870eb1 100644 --- a/Doc/library/re.rst +++ b/Doc/library/re.rst @@ -414,17 +414,24 @@ Most of the standard escapes supported by Python string literals are also accepted by the regular expression parser:: \a \b \f \n - \r \t \v \x - \\ + \r \t \u \U + \v \x \\ (Note that ``\b`` is used to represent word boundaries, and means "backspace" only inside character classes.) +``'\u'`` and ``'\U'`` escape sequences are only recognized in Unicode +patterns. In bytes patterns they are not treated specially. + Octal escapes are included in a limited form. If the first digit is a 0, or if there are three octal digits, it is considered an octal escape. Otherwise, it is a group reference. As for string literals, octal escapes are always at most three digits in length. +.. versionchanged:: 3.3 + The ``'\u'`` and ``'\U'`` escape sequences have been added. + + .. _contents-of-module-re: @@ -684,9 +691,12 @@ form. .. function:: escape(string) - Return *string* with all non-alphanumerics backslashed; this is useful if you - want to match an arbitrary literal string that may have regular expression - metacharacters in it. + 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. + + .. versionchanged:: 3.3 + The ``'_'`` character is no longer escaped. .. function:: purge() |