Author: brian.curtin Date: Fri Mar 26 03:29:25 2010 New Revision: 79435 Log: Merged revisions 79434 via svnmerge from svn+ssh://pythondev@svn.python.org/python/branches/py3k ................ r79434 | brian.curtin | 2010-03-25 19:39:56 -0500 (Thu, 25 Mar 2010) | 9 lines Merged revisions 79430 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r79430 | brian.curtin | 2010-03-25 18:48:54 -0500 (Thu, 25 Mar 2010) | 2 lines Fix #6538. Markup RegexObject and MatchObject as classes. Patch by Ryan Arana. ........ ................ Modified: python/branches/release31-maint/Doc/library/re.rst Modified: python/branches/release31-maint/Doc/library/re.rst ============================================================================== --- python/branches/release31-maint/Doc/library/re.rst (original) +++ python/branches/release31-maint/Doc/library/re.rst Fri Mar 26 03:29:25 2010 @@ -705,98 +705,99 @@ Regular Expression Objects -------------------------- -Compiled regular expression objects support the following methods and -attributes: +.. class:: RegexObject + The :class:`RegexObject` class supports the following methods and attributes: -.. method:: RegexObject.match(string[, pos[, endpos]]) - If zero or more characters at the beginning of *string* match this regular - expression, return a corresponding :class:`MatchObject` instance. Return - ``None`` if the string does not match the pattern; note that this is different - from a zero-length match. + .. method:: RegexObject.match(string[, pos[, endpos]]) - .. note:: + If zero or more characters at the beginning of *string* match this regular + expression, return a corresponding :class:`MatchObject` instance. Return + ``None`` if the string does not match the pattern; note that this is different + from a zero-length match. - If you want to locate a match anywhere in *string*, use - :meth:`~RegexObject.search` instead. + .. note:: - The optional second parameter *pos* gives an index in the string where the - search is to start; it defaults to ``0``. This is not completely equivalent to - slicing the string; the ``'^'`` pattern character matches at the real beginning - of the string and at positions just after a newline, but not necessarily at the - index where the search is to start. + If you want to locate a match anywhere in *string*, use + :meth:`~RegexObject.search` instead. - The optional parameter *endpos* limits how far the string will be searched; it - will be as if the string is *endpos* characters long, so only the characters - from *pos* to ``endpos - 1`` will be searched for a match. If *endpos* is less - than *pos*, no match will be found, otherwise, if *rx* is a compiled regular - expression object, ``rx.match(string, 0, 50)`` is equivalent to - ``rx.match(string[:50], 0)``. + The optional second parameter *pos* gives an index in the string where the + search is to start; it defaults to ``0``. This is not completely equivalent to + slicing the string; the ``'^'`` pattern character matches at the real beginning + of the string and at positions just after a newline, but not necessarily at the + index where the search is to start. - >>> pattern = re.compile("o") - >>> pattern.match("dog") # No match as "o" is not at the start of "dog." - >>> pattern.match("dog", 1) # Match as "o" is the 2nd character of "dog". - <_sre.SRE_Match object at ...> + The optional parameter *endpos* limits how far the string will be searched; it + will be as if the string is *endpos* characters long, so only the characters + from *pos* to ``endpos - 1`` will be searched for a match. If *endpos* is less + than *pos*, no match will be found, otherwise, if *rx* is a compiled regular + expression object, ``rx.match(string, 0, 50)`` is equivalent to + ``rx.match(string[:50], 0)``. + >>> pattern = re.compile("o") + >>> pattern.match("dog") # No match as "o" is not at the start of "dog." + >>> pattern.match("dog", 1) # Match as "o" is the 2nd character of "dog". + <_sre.SRE_Match object at ...> -.. method:: RegexObject.search(string[, pos[, endpos]]) - Scan through *string* looking for a location where this regular expression - produces a match, and return a corresponding :class:`MatchObject` instance. - Return ``None`` if no position in the string matches the pattern; note that this - is different from finding a zero-length match at some point in the string. + .. method:: RegexObject.search(string[, pos[, endpos]]) - The optional *pos* and *endpos* parameters have the same meaning as for the - :meth:`~RegexObject.match` method. + Scan through *string* looking for a location where this regular expression + produces a match, and return a corresponding :class:`MatchObject` instance. + Return ``None`` if no position in the string matches the pattern; note that this + is different from finding a zero-length match at some point in the string. + The optional *pos* and *endpos* parameters have the same meaning as for the + :meth:`~RegexObject.match` method. -.. method:: RegexObject.split(string[, maxsplit=0]) - Identical to the :func:`split` function, using the compiled pattern. + .. method:: RegexObject.split(string[, maxsplit=0]) + Identical to the :func:`split` function, using the compiled pattern. -.. method:: RegexObject.findall(string[, pos[, endpos]]) - Identical to the :func:`findall` function, using the compiled pattern. + .. method:: RegexObject.findall(string[, pos[, endpos]]) + Identical to the :func:`findall` function, using the compiled pattern. -.. method:: RegexObject.finditer(string[, pos[, endpos]]) - Identical to the :func:`finditer` function, using the compiled pattern. + .. method:: RegexObject.finditer(string[, pos[, endpos]]) + Identical to the :func:`finditer` function, using the compiled pattern. -.. method:: RegexObject.sub(repl, string[, count=0]) - Identical to the :func:`sub` function, using the compiled pattern. + .. method:: RegexObject.sub(repl, string[, count=0]) + Identical to the :func:`sub` function, using the compiled pattern. -.. method:: RegexObject.subn(repl, string[, count=0]) - Identical to the :func:`subn` function, using the compiled pattern. + .. method:: RegexObject.subn(repl, string[, count=0]) + Identical to the :func:`subn` function, using the compiled pattern. -.. attribute:: RegexObject.flags - The flags argument used when the RE object was compiled, or ``0`` if no flags - were provided. + .. attribute:: RegexObject.flags + The flags argument used when the RE object was compiled, or ``0`` if no flags + were provided. -.. attribute:: RegexObject.groups - The number of capturing groups in the pattern. + .. attribute:: RegexObject.groups + The number of capturing groups in the pattern. -.. attribute:: RegexObject.groupindex - A dictionary mapping any symbolic group names defined by ``(?P<id>)`` to group - numbers. The dictionary is empty if no symbolic groups were used in the - pattern. + .. attribute:: RegexObject.groupindex + A dictionary mapping any symbolic group names defined by ``(?P<id>)`` to group + numbers. The dictionary is empty if no symbolic groups were used in the + pattern. -.. attribute:: RegexObject.pattern - The pattern string from which the RE object was compiled. + .. attribute:: RegexObject.pattern + + The pattern string from which the RE object was compiled. .. _match-objects: @@ -804,176 +805,180 @@ Match Objects ------------- -Match objects always have a boolean value of :const:`True`, so that you can test -whether e.g. :func:`match` resulted in a match with a simple if statement. They -support the following methods and attributes: +.. class:: MatchObject + Match Objects always have a boolean value of :const:`True`, so that you can test + whether e.g. :func:`match` resulted in a match with a simple if statement. They + support the following methods and attributes: -.. method:: MatchObject.expand(template) - Return the string obtained by doing backslash substitution on the template - string *template*, as done by the :meth:`~RegexObject.sub` method. Escapes - such as ``\n`` are converted to the appropriate characters, and numeric - backreferences (``\1``, ``\2``) and named backreferences (``\g<1>``, - ``\g<name>``) are replaced by the contents of the corresponding group. + .. method:: MatchObject.expand(template) + Return the string obtained by doing backslash substitution on the template + string *template*, as done by the :meth:`~RegexObject.sub` method. Escapes + such as ``\n`` are converted to the appropriate characters, and numeric + backreferences (``\1``, ``\2``) and named backreferences (``\g<1>``, + ``\g<name>``) are replaced by the contents of the corresponding group. -.. method:: MatchObject.group([group1, ...]) - Returns one or more subgroups of the match. If there is a single argument, the - result is a single string; if there are multiple arguments, the result is a - tuple with one item per argument. Without arguments, *group1* defaults to zero - (the whole match is returned). If a *groupN* argument is zero, the corresponding - return value is the entire matching string; if it is in the inclusive range - [1..99], it is the string matching the corresponding parenthesized group. If a - group number is negative or larger than the number of groups defined in the - pattern, an :exc:`IndexError` exception is raised. If a group is contained in a - part of the pattern that did not match, the corresponding result is ``None``. - If a group is contained in a part of the pattern that matched multiple times, - the last match is returned. + .. method:: MatchObject.group([group1, ...]) - >>> m = re.match(r"(\w+) (\w+)", "Isaac Newton, physicist") - >>> m.group(0) # The entire match - 'Isaac Newton' - >>> m.group(1) # The first parenthesized subgroup. - 'Isaac' - >>> m.group(2) # The second parenthesized subgroup. - 'Newton' - >>> m.group(1, 2) # Multiple arguments give us a tuple. - ('Isaac', 'Newton') + Returns one or more subgroups of the match. If there is a single argument, the + result is a single string; if there are multiple arguments, the result is a + tuple with one item per argument. Without arguments, *group1* defaults to zero + (the whole match is returned). If a *groupN* argument is zero, the corresponding + return value is the entire matching string; if it is in the inclusive range + [1..99], it is the string matching the corresponding parenthesized group. If a + group number is negative or larger than the number of groups defined in the + pattern, an :exc:`IndexError` exception is raised. If a group is contained in a + part of the pattern that did not match, the corresponding result is ``None``. + If a group is contained in a part of the pattern that matched multiple times, + the last match is returned. - If the regular expression uses the ``(?P<name>...)`` syntax, the *groupN* - arguments may also be strings identifying groups by their group name. If a - string argument is not used as a group name in the pattern, an :exc:`IndexError` - exception is raised. + >>> m = re.match(r"(\w+) (\w+)", "Isaac Newton, physicist") + >>> m.group(0) # The entire match + 'Isaac Newton' + >>> m.group(1) # The first parenthesized subgroup. + 'Isaac' + >>> m.group(2) # The second parenthesized subgroup. + 'Newton' + >>> m.group(1, 2) # Multiple arguments give us a tuple. + ('Isaac', 'Newton') - A moderately complicated example: + If the regular expression uses the ``(?P<name>...)`` syntax, the *groupN* + arguments may also be strings identifying groups by their group name. If a + string argument is not used as a group name in the pattern, an :exc:`IndexError` + exception is raised. - >>> m = re.match(r"(?P<first_name>\w+) (?P<last_name>\w+)", "Malcolm Reynolds") - >>> m.group('first_name') - 'Malcolm' - >>> m.group('last_name') - 'Reynolds' + A moderately complicated example: - Named groups can also be referred to by their index: + >>> m = re.match(r"(?P<first_name>\w+) (?P<last_name>\w+)", "Malcolm Reynolds") + >>> m.group('first_name') + 'Malcolm' + >>> m.group('last_name') + 'Reynolds' - >>> m.group(1) - 'Malcolm' - >>> m.group(2) - 'Reynolds' + Named groups can also be referred to by their index: - If a group matches multiple times, only the last match is accessible: + >>> m.group(1) + 'Malcolm' + >>> m.group(2) + 'Reynolds' - >>> m = re.match(r"(..)+", "a1b2c3") # Matches 3 times. - >>> m.group(1) # Returns only the last match. - 'c3' + If a group matches multiple times, only the last match is accessible: + >>> m = re.match(r"(..)+", "a1b2c3") # Matches 3 times. + >>> m.group(1) # Returns only the last match. + 'c3' -.. method:: MatchObject.groups([default]) + .. method:: MatchObject.groups([default]) - Return a tuple containing all the subgroups of the match, from 1 up to however - many groups are in the pattern. The *default* argument is used for groups that - did not participate in the match; it defaults to ``None``. + Return a tuple containing all the subgroups of the match, from 1 up to however + many groups are in the pattern. The *default* argument is used for groups that + did not participate in the match; it defaults to ``None``. (Incompatibility + note: in the original Python 1.5 release, if the tuple was one element long, a + string would be returned instead. In later versions (from 1.5.1 on), a + singleton tuple is returned in such cases.) - For example: + For example: - >>> m = re.match(r"(\d+)\.(\d+)", "24.1632") - >>> m.groups() - ('24', '1632') + >>> m = re.match(r"(\d+)\.(\d+)", "24.1632") + >>> m.groups() + ('24', '1632') - If we make the decimal place and everything after it optional, not all groups - might participate in the match. These groups will default to ``None`` unless - the *default* argument is given: + If we make the decimal place and everything after it optional, not all groups + might participate in the match. These groups will default to ``None`` unless + the *default* argument is given: - >>> m = re.match(r"(\d+)\.?(\d+)?", "24") - >>> m.groups() # Second group defaults to None. - ('24', None) - >>> m.groups('0') # Now, the second group defaults to '0'. - ('24', '0') + >>> m = re.match(r"(\d+)\.?(\d+)?", "24") + >>> m.groups() # Second group defaults to None. + ('24', None) + >>> m.groups('0') # Now, the second group defaults to '0'. + ('24', '0') -.. method:: MatchObject.groupdict([default]) + .. method:: MatchObject.groupdict([default]) - Return a dictionary containing all the *named* subgroups of the match, keyed by - the subgroup name. The *default* argument is used for groups that did not - participate in the match; it defaults to ``None``. For example: + Return a dictionary containing all the *named* subgroups of the match, keyed by + the subgroup name. The *default* argument is used for groups that did not + participate in the match; it defaults to ``None``. For example: - >>> m = re.match(r"(?P<first_name>\w+) (?P<last_name>\w+)", "Malcolm Reynolds") - >>> m.groupdict() - {'first_name': 'Malcolm', 'last_name': 'Reynolds'} + >>> m = re.match(r"(?P<first_name>\w+) (?P<last_name>\w+)", "Malcolm Reynolds") + >>> m.groupdict() + {'first_name': 'Malcolm', 'last_name': 'Reynolds'} -.. method:: MatchObject.start([group]) - MatchObject.end([group]) + .. method:: MatchObject.start([group]) + MatchObject.end([group]) - Return the indices of the start and end of the substring matched by *group*; - *group* defaults to zero (meaning the whole matched substring). Return ``-1`` if - *group* exists but did not contribute to the match. For a match object *m*, and - a group *g* that did contribute to the match, the substring matched by group *g* - (equivalent to ``m.group(g)``) is :: + Return the indices of the start and end of the substring matched by *group*; + *group* defaults to zero (meaning the whole matched substring). Return ``-1`` if + *group* exists but did not contribute to the match. For a match object *m*, and + a group *g* that did contribute to the match, the substring matched by group *g* + (equivalent to ``m.group(g)``) is :: - m.string[m.start(g):m.end(g)] + m.string[m.start(g):m.end(g)] - Note that ``m.start(group)`` will equal ``m.end(group)`` if *group* matched a - null string. For example, after ``m = re.search('b(c?)', 'cba')``, - ``m.start(0)`` is 1, ``m.end(0)`` is 2, ``m.start(1)`` and ``m.end(1)`` are both - 2, and ``m.start(2)`` raises an :exc:`IndexError` exception. + Note that ``m.start(group)`` will equal ``m.end(group)`` if *group* matched a + null string. For example, after ``m = re.search('b(c?)', 'cba')``, + ``m.start(0)`` is 1, ``m.end(0)`` is 2, ``m.start(1)`` and ``m.end(1)`` are both + 2, and ``m.start(2)`` raises an :exc:`IndexError` exception. - An example that will remove *remove_this* from email addresses: + An example that will remove *remove_this* from email addresses: - >>> email = "tony@tiremove_thisger.net" - >>> m = re.search("remove_this", email) - >>> email[:m.start()] + email[m.end():] - 'tony@tiger.net' + >>> email = "tony@tiremove_thisger.net" + >>> m = re.search("remove_this", email) + >>> email[:m.start()] + email[m.end():] + 'tony@tiger.net' -.. method:: MatchObject.span([group]) + .. method:: MatchObject.span([group]) - For :class:`MatchObject` *m*, return the 2-tuple ``(m.start(group), - m.end(group))``. Note that if *group* did not contribute to the match, this is - ``(-1, -1)``. *group* defaults to zero, the entire match. + For :class:`MatchObject` *m*, return the 2-tuple ``(m.start(group), + m.end(group))``. Note that if *group* did not contribute to the match, this is + ``(-1, -1)``. *group* defaults to zero, the entire match. -.. attribute:: MatchObject.pos + .. attribute:: MatchObject.pos - The value of *pos* which was passed to the :meth:`~RegexObject.search` or - :meth:`~RegexObject.match` method of the :class:`RegexObject`. This is the - index into the string at which the RE engine started looking for a match. + The value of *pos* which was passed to the :meth:`~RegexObject.search` or + :meth:`~RegexObject.match` method of the :class:`RegexObject`. This is the + index into the string at which the RE engine started looking for a match. -.. attribute:: MatchObject.endpos + .. attribute:: MatchObject.endpos - The value of *endpos* which was passed to the :meth:`~RegexObject.search` or - :meth:`~RegexObject.match` method of the :class:`RegexObject`. This is the - index into the string beyond which the RE engine will not go. + The value of *endpos* which was passed to the :meth:`~RegexObject.search` or + :meth:`~RegexObject.match` method of the :class:`RegexObject`. This is the + index into the string beyond which the RE engine will not go. -.. attribute:: MatchObject.lastindex + .. attribute:: MatchObject.lastindex - The integer index of the last matched capturing group, or ``None`` if no group - was matched at all. For example, the expressions ``(a)b``, ``((a)(b))``, and - ``((ab))`` will have ``lastindex == 1`` if applied to the string ``'ab'``, while - the expression ``(a)(b)`` will have ``lastindex == 2``, if applied to the same - string. + The integer index of the last matched capturing group, or ``None`` if no group + was matched at all. For example, the expressions ``(a)b``, ``((a)(b))``, and + ``((ab))`` will have ``lastindex == 1`` if applied to the string ``'ab'``, while + the expression ``(a)(b)`` will have ``lastindex == 2``, if applied to the same + string. -.. attribute:: MatchObject.lastgroup + .. attribute:: MatchObject.lastgroup - The name of the last matched capturing group, or ``None`` if the group didn't - have a name, or if no group was matched at all. + The name of the last matched capturing group, or ``None`` if the group didn't + have a name, or if no group was matched at all. -.. attribute:: MatchObject.re + .. attribute:: MatchObject.re - The regular expression object whose :meth:`~RegexObject.match` or - :meth:`~RegexObject.search` method produced this :class:`MatchObject` - instance. + The regular expression object whose :meth:`~RegexObject.match` or + :meth:`~RegexObject.search` method produced this :class:`MatchObject` + instance. -.. attribute:: MatchObject.string + .. attribute:: MatchObject.string - The string passed to :meth:`~RegexObject.match` or - :meth:`~RegexObject.search`. + The string passed to :meth:`~RegexObject.match` or + :meth:`~RegexObject.search`. Examples