Why won't re.groups() give me anything for my one correctly-matched group?


Question

When I run this code:

print re.search(r'1', '1').groups() 

I get a result of (). However, .group(0) gives me the match.

Shouldn't groups() give me something containing the match?

Update: Thanks for the answers. So that means if I do re.search() with no subgroups, I have to use groups(0) to get a match?

1
28
11/14/2017 11:47:15 PM

Accepted Answer

groups is empty since you do not have any capturing groups - http://docs.python.org/library/re.html#re.MatchObject.groups. group(0) will always returns the whole text that was matched regardless of if it was captured in a group or not

Edited.

20
9/5/2011 7:42:44 PM

To the best of my knowledge, .groups() returns a tuple of remembered groups. I.e. those groups in the regular expression that are enclosed in parentheses. So if you were to write:

print re.search(r'(1)', '1').groups()

you would get

('1',)

as your response. In general, .groups() will return a tuple of all the groups of objects in the regular expression that are enclosed within parentheses.


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