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  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.
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Brian Curtin 2010-03-26 00:39:56 +00:00
parent fa0aebacd9
commit 027e478f3f
1 changed files with 183 additions and 180 deletions

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@ -705,98 +705,99 @@ form.
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]])
.. 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.
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.
.. note::
.. note::
If you want to locate a match anywhere in *string*, use
:meth:`~RegexObject.search` instead.
If you want to locate a match anywhere in *string*, use
:meth:`~RegexObject.search` instead.
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.
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.
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 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 ...>
>>> 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]])
.. 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.
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.
The optional *pos* and *endpos* parameters have the same meaning as for the
:meth:`~RegexObject.match` method.
.. method:: RegexObject.split(string, maxsplit=0)
.. method:: RegexObject.split(string[, maxsplit=0])
Identical to the :func:`split` function, using the compiled pattern.
Identical to the :func:`split` function, using the compiled pattern.
.. method:: RegexObject.findall(string[, pos[, endpos]])
.. method:: RegexObject.findall(string[, pos[, endpos]])
Identical to the :func:`findall` function, using the compiled pattern.
Identical to the :func:`findall` function, using the compiled pattern.
.. method:: RegexObject.finditer(string[, pos[, endpos]])
.. method:: RegexObject.finditer(string[, pos[, endpos]])
Identical to the :func:`finditer` function, using the compiled pattern.
Identical to the :func:`finditer` function, using the compiled pattern.
.. method:: RegexObject.sub(repl, string, count=0)
.. method:: RegexObject.sub(repl, string[, count=0])
Identical to the :func:`sub` function, using the compiled pattern.
Identical to the :func:`sub` function, using the compiled pattern.
.. method:: RegexObject.subn(repl, string, count=0)
.. method:: RegexObject.subn(repl, string[, count=0])
Identical to the :func:`subn` function, using the compiled pattern.
Identical to the :func:`subn` function, using the compiled pattern.
.. attribute:: RegexObject.flags
.. attribute:: RegexObject.flags
The flags argument used when the RE object was compiled, or ``0`` if no flags
were provided.
The flags argument used when the RE object was compiled, or ``0`` if no flags
were provided.
.. attribute:: RegexObject.groups
.. attribute:: RegexObject.groups
The number of capturing groups in the pattern.
The number of capturing groups in the pattern.
.. attribute:: RegexObject.groupindex
.. 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.
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
.. attribute:: RegexObject.pattern
The pattern string from which the RE object was compiled.
The pattern string from which the RE object was compiled.
.. _match-objects:
@ -804,176 +805,178 @@ attributes:
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)
.. 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.
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, ...])
.. 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.
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.
>>> 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')
>>> 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')
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.
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.
A moderately complicated example:
A moderately complicated example:
>>> 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 = re.match(r"(?P<first_name>\w+) (?P<last_name>\w+)", "Malcolm Reynolds")
>>> m.group('first_name')
'Malcolm'
>>> m.group('last_name')
'Reynolds'
Named groups can also be referred to by their index:
Named groups can also be referred to by their index:
>>> m.group(1)
'Malcolm'
>>> m.group(2)
'Reynolds'
>>> m.group(1)
'Malcolm'
>>> m.group(2)
'Reynolds'
If a group matches multiple times, only the last match is accessible:
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'
>>> m = re.match(r"(..)+", "a1b2c3") # Matches 3 times.
>>> m.group(1) # Returns only the last match.
'c3'
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:
>>> 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:
>>> 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.groups(default=None)
.. method:: MatchObject.groupdict([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 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:
For example:
>>> 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:
>>> 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"(?P<first_name>\w+) (?P<last_name>\w+)", "Malcolm Reynolds")
>>> m.groupdict()
{'first_name': 'Malcolm', 'last_name': 'Reynolds'}
.. method:: MatchObject.groupdict(default=None)
.. method:: MatchObject.start([group])
MatchObject.end([group])
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 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 = re.match(r"(?P<first_name>\w+) (?P<last_name>\w+)", "Malcolm Reynolds")
>>> m.groupdict()
{'first_name': 'Malcolm', 'last_name': 'Reynolds'}
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.
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'
.. method:: MatchObject.start(group=0)
MatchObject.end(group=0)
.. method:: MatchObject.span([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 ::
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.
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'
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.
.. method:: MatchObject.span(group=0)
.. attribute:: MatchObject.pos
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.
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.pos
.. attribute:: MatchObject.endpos
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 *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.endpos
.. attribute:: MatchObject.lastindex
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 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.lastindex
.. attribute:: MatchObject.lastgroup
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 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.lastgroup
.. attribute:: MatchObject.re
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 regular expression object whose :meth:`~RegexObject.match` or
:meth:`~RegexObject.search` method produced this :class:`MatchObject`
instance.
.. attribute:: MatchObject.re
.. attribute:: MatchObject.string
The regular expression object whose :meth:`~RegexObject.match` or
:meth:`~RegexObject.search` method produced this :class:`MatchObject`
instance.
.. 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