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If you are doing something heavy on regular expression, then you are much better off with re2 from google.

https://swtch.com/~rsc/regexp/regexp1.html

Also re is running in python, whereas re2 is written in C (with python language bindings)

I wonder, why python didn't ditch the built-in re package in favor of re2... That might be due to some compatibility issues, but i don't know anything specific.

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Because re2 doesn't support everything POSIX regex support.

Why does it matter? Python's re doesn't support all POSIX ERE constructs either.

Are you able to qualify: Better off in what way? The built-in re package has always been sufficient for me and I dream in regex.

re2 is using state machines to evaluate everything in linear time. Backtracking re implementations have some very slow edge cases.

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