Regular Expressions...

Question

How would I extract the word 'wrestle' from the following:

type=weaksubj len=1 word1=wrestle pos1=verb stemmed1=y priorpolarity=negative

using a regular expression?

Thanks

Answer 1

You regex would be something like this

/.*word1=(\w+)/

Answer 2

Use: /word1=(\w+)/

Answer 3

Given the following regex...

/word1=(\w+)/

...$1 or whatever your first match is in your language will be wrestle.

Answer 4

Assuming it is always separated by spaces

word1=([^ ]+)

Then you can get the value by the first group match.

Answer 5

The question is not very clear, but I guess this is what you are looking for:

word1=(\w+)

Your match will be in the 1st group. Here's some sample Python code:

import re
yourstring = 'type=weaksubj len=1 word1=wrestle pos1=verb stemmed1=y priorpolarity=negative'

m = re.search(r'word1=(\w+)', yourstring)
print m.group(1)

As seen on codepad. A more generalized solution:

import re
def get_attr(str, attr):
    m = re.search(attr + r'=(\w+)', str)
    return None if not m else m.group(1)

str = 'type=weaksubj len=1 word1=wrestle pos1=verb stemmed1=y priorpolarity=negative'

print get_attr(str, 'word1')  # wrestle
print get_attr(str, 'type')   # weaksubj
print get_attr(str, 'foo')    # None

Also available on codepad

Answer 6

Maybe re is unnecessary when str.split looks like it will suffice:

>>> s = "type=weaksubj len=1 word1=wrestle pos1=verb stemmed1=y priorpolarity=negative"
>>> dd = dict(ss.split('=',1) for ss in s.split())
>>> dd['word1']
'wrestle'