Python Regex - grab a block of whitespace from end of string

Question

I am trying to write a regex that grabs blocks of whitespace from either side of a string. I can get the beginning, but I can't seem to grab the end block.

s = '     This is a string with whitespace on either side     '

strip_regex = re.compile(r'(\s+)(.*)(something to grab end block)')
mo = strip_regex.findall(s)

What I get as an output is this:

[('        ', 'This is a string with whitespace on either side        ')]

I have played around with that to do at the end, and the best I can get is one whitespace but I can never just grab the string until the end of 'side'. I don't want to use the characters in side because I want the regex to work with any string surrounded by whitespace. I am pretty sure that it's because I am using the (.*) which is just grabbing everything after the first whitespace block. But can't figure out how to make it stop before the end whitespace block.

Thanks for any help :)

estherwn · Accepted Answer · 2020-05-07 09:53:15Z

1

If what you want to do is strip whitespace, you could use strip() instead. See: https://www.journaldev.com/23625/python-trim-string-rstrip-lstrip-strip

As for your regex, if you want both the start and end whitespace, I suggest matching the whole line, with the middle part not greedy like so:

s = '     This is a string with whitespace on either side     '
strip_regex = re.compile(r'^(\s+)(.*?)(\s+)$')
mo = strip_regex.findall(s)

Result:

[('     ', 'This is a string with whitespace on either side', '     ')]

More about greedy: How can I write a regex which matches non greedy?

answered May 7, 2020 at 9:53

estherwn

1866 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Arcadia_Lake Over a year ago

That's awesome thank you! Literally just had to move the $ outside of the last group and it would have worked! I was trying to write a regex which would imitate the strip() function :)

Collectives™ on Stack Overflow

Python Regex - grab a block of whitespace from end of string

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related