Python regex (.*?) isn't giving an output

Question

I'm making a project and part of it is taking in a python file as a text file and parsing it using regular expressions.

I was able to use this fine (where program is a string containing the code with newlines):

findall(r"def (.*?)\((.*?)\)", program)

But this line just gives None when I expect it to give a Match object where .group() returns "func1(None, None)"

mainblock = search(r'if __name__ == "__main__":(.*?)#END', program)

An abbreviated version of the python file I'm parsing is below:

def func1(stuff, morestuff):
    pass

if __name__ == "__main__":
    func1(None, None)
#END

I've checked for any discrepencies in the regex itself and I can't find any. I also tried copy/pasting it directly from the code file and it still couldn't find a match

Yes, program is just a long string with the program in and I also tried adding multiline - it still couldn't find it — Simon Toogood, Dec 13 '18 at 23:02
`.*?` doesn't go across newlines unless you use the `re.MULTILINE` modifier. — Barmar, Dec 13 '18 at 23:08
Yeah, got confused there. The answer below got the right flag. — Barmar, Dec 13 '18 at 23:11

mkrieger1 · Accepted Answer · 2018-12-13T23:13:44.880

2

You need to either include the newline characters \n in the regular expression, like this,

r'if __name__ == "__main__":\n(.*?)\n#END'

or enable the DOTALL flag, meaning that . also matches line breaks.

(MULTILINE means something else, which can be counterintuitive.)

edited Dec 13 '18 at 23:13

answered Dec 13 '18 at 23:10

mkrieger1

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Here's a working demo of DOTALL. https://ideone.com/rS2slo – Barmar Dec 13 '18 at 23:12
DOTALL worked perfectly – Simon Toogood Dec 13 '18 at 23:13
1

MULTILINE should have been named something like ANCHOR_TO_LINE.... – Barmar Dec 13 '18 at 23:14

Python regex (.*?) isn't giving an output

1 Answers1