Python Match Group

Question

I'm having trouble creating a match group to extract two values from a string using python

Here's my input:

# SomeKey: Value Is A String

And I'd like to be able to extract SomeKey and Value Is A String using a python match group / regex statement. Here's what I have so far

import re
line = "# SomeKey: Value Is A String"
mg = re.match(r"# <key>: <value>", line)

score 1 · Accepted Answer · edited May 05 '14 at 12:30

1

You have to provide the string you're matching:

import re
line = "# SomeKey: Value Is A String"
mg = re.match(r"# ([^:]+): (.*)", line)

>>> print mg.group(1)
SomeKey
>>> print mg.group(2)
Value Is A String

Or to automatically get a tuple of key and value, you can do:

import re
line = "# SomeKey: Value Is A String"
mg = re.findall(r"# ([^:]+): (.*)", line)

>>> print mg
[('SomeKey', 'Value Is A String')]

DEMO

For names, you would do:

mg = re.match(r"# (?P<key>[^:]+): (?P<value>.*)", line)
print mg.group('key')

DEMO

edited May 05 '14 at 12:30

Wooble

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answered May 05 '14 at 11:11

sshashank124

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I mistyped my question. Thanks for the quick answer – JonMorehouse May 05 '14 at 11:11
how can I use the named group? – JonMorehouse May 05 '14 at 11:17
its something like () I believe – JonMorehouse May 05 '14 at 11:17
@JonMorehouse, What do you mean. Meanwhile, I have updated my answer yet again – sshashank124 May 05 '14 at 11:17
@JonMorehouse, Answer updated to include named groups. – sshashank124 May 05 '14 at 11:21
this is what I meant: `mg = re.match(r"# (?P[^:]+): (?P.*)", line)` – JonMorehouse May 05 '14 at 11:21

score 0 · Answer 2 · answered May 05 '14 at 11:17

Unless your real use-case is way more complicated, you can directly unpack the values into the corresponding variables by using findall like this:

import re
line = "# SomeKey: Value Is A String"
key, val = re.findall(r"# (.*?): (.*)$", line)[0]
# (key, val) == ('SomeKey', 'Value Is A String')

Python Match Group

2 Answers2