[Python-ideas] New explicit methods to trim strings

Brandt Bucher brandtbucher at gmail.com
Sat Mar 30 20:27:48 EDT 2019

> One thing I love about .startswith() and .endswith() is matching multiple options. It's a little funny the multiple options must be a tuple exactly (not a list, not a set, not an iterator), but whatever. It would be about to lack that symmetry in the .cut_suffix() method.
> E.g now:
>   if fname.endswith(('.jpg', '.png', '.gif)): ...
> I'd expect to be able to do:
>   basename = fname.cut_suffix(('.jpg', '.png', '.gif))

An idea worth considering: one can think of the “strip” family of methods as currently taking an iterable of strings as an argument (since a string is itself an sequence of strings):

>>> "abcd".rstrip("dc")

It would not be a huge logical leap to allow them to take any iterable. Backward compatible, no new methods:

>>> fname.rstrip(('.jpg', '.png', '.gif'))

It even, in my opinion, can clarify "classic" strip/rstrip/lstrip usage:

>>> "abcd".rstrip(("d", "c"))

Maybe I’m missing a breaking case though, or this isn’t as clear for others. Thoughts?


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