CODEWITHSUNDEEP
pythonregexpython-3.x
user1054158
user1054158

Reputation:

Finding in regex pattern the name of possible groups

Let's consider the string r"(?P<DEF_FUNC>def (?P<NAME_FUNC>\w+)\s*\((.*?)\):)|(?P<OTHERS>\w+)" which be used later for defining a pattern.

I would like to find in this string the names used for defining the groups from the regex's point of view. Here, this names are DEF_FUNC, NAME_FUNC and OTHERS.

How can I achieve that by taking care of escaping issues ?

Upvotes: 1

Views: 53

Answers (1)

DSM
DSM

Reputation: 353139

You can find them in the groupindex dictionary (see docs here):

>>> import re
>>> rstr = r"(?P<DEF_FUNC>def (?P<NAME_FUNC>\w+)\s*\((.*?)\):)|(?P<OTHERS>\w+)"
>>> regex = re.compile(rstr)   
>>> regex.groupindex
{'DEF_FUNC': 1, 'OTHERS': 4, 'NAME_FUNC': 2}

Doing the usual tricks if you want them in value order:

>>> sorted(regex.groupindex, key=regex.groupindex.get)
['DEF_FUNC', 'NAME_FUNC', 'OTHERS']

Upvotes: 2

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