python regex: to match space character or end of string

Question

I want to match space chars or end of string in a text.

import re


uname='abc'
assert re.findall('@%s\s*$' % uname, '@'+uname)
assert re.findall('@%s\s*$' % uname, '@'+uname+'  '+'aa')
assert not re.findall('@%s\s*$' % uname, '@'+uname+'aa')

The pattern is not right.
How to use python?

Answer 1

\s*$ is incorrect: this matches "zero or more spaces followed by the end of the string", rather than "one or more spaces or the end of the string".

For this situation, I would use (?:\s+|$) (inside a raw string, as others have mentioned). The (?:) part is just about separating that subexpression so that the | operator matches the correct fragment and no more than the correct fragment.