Python 正则表达式 理解边界“\b”

Question

input:

- "example (.com)"

output:

- "example"

What I tried

import re
pattern=re.compile(r'\b\([\W\w]+\)\b')
#pattern=re.compile(r'\([\W\w]+\)')
print(pattern.sub("","example (.com)"))

This doesn't work but if I remove \b it works fine - why?

Answer 1

Make yourself clear what the \b stands for:

(?:(?=\w)(?<!\w)|(?<=\w)(?!\w))

That is, either a word character ahead and not behind or the other way round. A word character ( \w ) stands for [A-Za-z0-9_] and does not include ( or ) , so there's no word boundary between a space and a parenthesis.

Answer 2

( is not a word boundary, so \b won't match it. Instead you could use \B to match the blank