I wrote a TUI application to help you practice Python regular expressions. There are more than 100 exercises covering both the builtin re and third-party regex module.

If you have pipx, use pipx install regexexercises to install the app. See the repo for source code and other details.

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[–] alyth@lemmy.world 1 points 1 year ago (1 children)

Thanks for sharing this. I took the time to read through the documentation of the re module. Here's my review of the functions.

Useful:

re.finditer returns an iterator over all Match objects
re.search returns the first Match object or None if there are no matches.
r'' use raw strings for patters so you don't have to worry about backslashes
the optional flags argument modifies the behaviour (case insensitive, multiline)

Utility:

re.sub replace each match in the string
re.split split a string by a regular expression

The Match object:

match.groups(0) returns the portion of text matched by the pattern
match.groups(1) returns the first capturing group
match.groups(2) returns the second capturing group, and so on

I don't understand why these exist:

re.match like search, but only matches at the beginning of the string. why not just use '^' or '\A' in the pattern you pass to 'search'?
re.fullmatch like 'search', but only if the full string matches. Why not just use '\A' and '\Z' in the pattern you pass to 'search'?
re.findall Returns all matches. It seems like a shitty version of 'finditer'. The function has three different return types which depend on the pattern you pattern you pass to the function. Who wants to work with that?