[Python-ideas] Easily remove characters from a string.

[Michel Desmoulin]

Le 22/10/2016 à 10:34, Simon Mark Holland a écrit :
> Having researched this as heavily as I am capable with limited
> experience, I would like to suggest a Python 3 equivalent to
> string.translate() that doesn't require a table as input.  Maybe in the
> form of str.stripall() or str.replaceall().
>
> My reasoning is that while it is currently possible to easily strip()
> preceding and trailing characters, and even replace() individual
> characters from a string, to replace more than one characters from
> anywhere within the string requires (i believe) at its simplest a
> command like this :
>
> some_string.translate(str.maketrans('','','0123456789'))
>
> In Python 2.* however we could say ...
>
> some_string.translate(None, '0123456789')
>
> My proposal is that if strip() and replace() are important enough to
> receive modules, then the arguably more common operation (in terms of
> programming tutorials, if not mainstream development) of just removing
> all instances of specified numbers, punctuation, or even letters etc
> from a list of characters should also.
>
> I wholeheartedly admit that there are MANY other ways to do this
> (including RegEx and List Comprehensions), as listed in the
> StackOverflow answer below.   However the same could be said for
> replace() and strip().

This actually could be implemented directly in str.replace() without 
breaking the API by accepting:

"stuff".replace('a', '')
"stuff".replace(('a', 'b', 'c'), '')
"stuff".replace(('a', 'b', 'c'), ('?', '*', ''))

A pure Python implementation looks like this:

https://github.com/Tygs/ww/blob/dev/src/ww/wrappers/strings.py#L229

(this implementation also allow regexes, which is not what you want for 
the builtin replace(), however, as it would break the performances 
expectations)

I often had the use case of needing to strip many strings so I would +1 
for having a nice and easy way to do it.