diff options
Diffstat (limited to 'Doc/library/re.rst')
| -rw-r--r-- | Doc/library/re.rst | 65 |
1 files changed, 47 insertions, 18 deletions
diff --git a/Doc/library/re.rst b/Doc/library/re.rst index 1ca621eca6..7ef4cbeee7 100644 --- a/Doc/library/re.rst +++ b/Doc/library/re.rst @@ -230,12 +230,8 @@ The special characters are: flags are described in :ref:`contents-of-module-re`.) This is useful if you wish to include the flags as part of the regular expression, instead of passing a *flag* argument to the - :func:`re.compile` function. - - Note that the ``(?x)`` flag changes how the expression is parsed. It should be - used first in the expression string, or after one or more whitespace characters. - If there are non-whitespace characters before the flag, the results are - undefined. + :func:`re.compile` function. Flags should be used first in the + expression string. ``(?:...)`` A non-capturing version of regular parentheses. Matches whatever regular @@ -243,6 +239,16 @@ The special characters are: *cannot* be retrieved after performing a match or referenced later in the pattern. +``(?imsx-imsx:...)`` + (Zero or more letters from the set ``'i'``, ``'m'``, ``'s'``, ``'x'``, + optionally followed by ``'-'`` followed by one or more letters from the + same set.) The letters set or removes the corresponding flags: + :const:`re.I` (ignore case), :const:`re.M` (multi-line), :const:`re.S` + (dot matches all), and :const:`re.X` (verbose), for the part of the + expression. (The flags are described in :ref:`contents-of-module-re`.) + + .. versionadded:: 3.6 + ``(?P<name>...)`` Similar to regular parentheses, but the substring matched by the group is accessible via the symbolic group name *name*. Group names must be valid @@ -327,8 +333,9 @@ The special characters are: The special sequences consist of ``'\'`` and a character from the list below. -If the ordinary character is not on the list, then the resulting RE will match -the second character. For example, ``\$`` matches the character ``'$'``. +If the ordinary character is not an ASCII digit or an ASCII letter, then the +resulting RE will match the second character. For example, ``\$`` matches the +character ``'$'``. ``\number`` Matches the contents of the group of the same number. Groups are numbered @@ -448,9 +455,8 @@ three digits in length. .. versionchanged:: 3.3 The ``'\u'`` and ``'\U'`` escape sequences have been added. -.. deprecated-removed:: 3.5 3.6 - Unknown escapes consisting of ``'\'`` and ASCII letter now raise a - deprecation warning and will be forbidden in Python 3.6. +.. versionchanged:: 3.6 + Unknown escapes consisting of ``'\'`` and an ASCII letter now are errors. .. seealso:: @@ -472,6 +478,9 @@ functions are simplified versions of the full featured methods for compiled regular expressions. Most non-trivial applications always use the compiled form. +.. versionchanged:: 3.6 + Flag constants are now instances of :class:`RegexFlag`, which is a subclass of + :class:`enum.IntFlag`. .. function:: compile(pattern, flags=0) @@ -538,11 +547,11 @@ form. current locale. The use of this flag is discouraged as the locale mechanism is very unreliable, and it only handles one "culture" at a time anyway; you should use Unicode matching instead, which is the default in Python 3 - for Unicode (str) patterns. This flag makes sense only with bytes patterns. + for Unicode (str) patterns. This flag can be used only with bytes patterns. - .. deprecated-removed:: 3.5 3.6 - Deprecated the use of :const:`re.LOCALE` with string patterns or - :const:`re.ASCII`. + .. versionchanged:: 3.6 + :const:`re.LOCALE` can be used only with bytes patterns and is + not compatible with :const:`re.ASCII`. .. data:: M @@ -748,9 +757,13 @@ form. .. versionchanged:: 3.5 Unmatched groups are replaced with an empty string. - .. deprecated-removed:: 3.5 3.6 - Unknown escapes consist of ``'\'`` and ASCII letter now raise a - deprecation warning and will be forbidden in Python 3.6. + .. versionchanged:: 3.6 + Unknown escapes in *pattern* consisting of ``'\'`` and an ASCII letter + now are errors. + + .. deprecated-removed:: 3.5 3.7 + Unknown escapes in *repl* consisting of ``'\'`` and an ASCII letter now raise + a deprecation warning and will be forbidden in Python 3.7. .. function:: subn(pattern, repl, string, count=0, flags=0) @@ -1016,6 +1029,22 @@ Match objects support the following methods and attributes: 'c3' +.. method:: match.__getitem__(g) + + This is identical to ``m.group(g)``. This allows easier access to + an individual group from a match: + + >>> m = re.match(r"(\w+) (\w+)", "Isaac Newton, physicist") + >>> m[0] # The entire match + 'Isaac Newton' + >>> m[1] # The first parenthesized subgroup. + 'Isaac' + >>> m[2] # The second parenthesized subgroup. + 'Newton' + + .. versionadded:: 3.6 + + .. method:: match.groups(default=None) Return a tuple containing all the subgroups of the match, from 1 up to however |