Python extract pattern matches

Question

Python 2.7.1 I am trying to use python regular expression to extract words inside of a pattern

I have some string that looks like this

someline abc
s         


        

Answer 1

You can use matching groups:

p = re.compile('name (.*) is valid')

e.g.

>>> import re
>>> p = re.compile('name (.*) is valid')
>>> s = """
... someline abc
... someother line
... name my_user_name is valid
... some more lines"""
>>> p.findall(s)
['my_user_name']

Here I use re.findall rather than re.search to get all instances of my_user_name. Using re.search, you'd need to get the data from the group on the match object:

>>> p.search(s)   #gives a match object or None if no match is found
<_sre.SRE_Match object at 0xf5c60>
>>> p.search(s).group() #entire string that matched
'name my_user_name is valid'
>>> p.search(s).group(1) #first group that match in the string that matched
'my_user_name'

---

As mentioned in the comments, you might want to make your regex non-greedy:

p = re.compile('name (.*?) is valid')

to only pick up the stuff between 'name ' and the next ' is valid' (rather than allowing your regex to pick up other ' is valid' in your group.