On 2019-03-31 16:48, David Mertz wrote:
The only reason I would support the idea would be to allow multiple suffixes (or prefixes). Otherwise, it just does too little for a new method. But adding that capability of startswith/endswith makes the cut off something easy to get wrong and non-trivial to implement.
That said, I really like Brandt's ideas of expanding the signature of .lstrip/.rstrip instead.
mystring.rstrip("abcd") # remove any of these single character suffixes
It removes _all_ of the single character suffixes.
mystring.rstrip(('foo', 'bar', 'baz')) # remove any of these suffixes
In keeping with the current behaviour, it would strip _all_ of these suffixes.
Yes, the semantics or removals where one is a substring of another would need to be decided. As long as it's documented, any behavior would be fine. Most of the time the issue would be moot.
On Sun, Mar 31, 2019, 4:36 AM Steven D'Aprano <steve@pearwood.info <mailto:steve@pearwood.info>> wrote:
On Sun, Mar 31, 2019 at 04:48:36PM +1100, Chris Angelico wrote:
> Regardless of the method name, IMO the functions should accept a tuple > of test strings, as startswith/endwith do. That's a feature that can't > easily be spelled in a one-liner. (Though stacked suffixes shouldn't > all be removed - "asdf.jpg.png".cutsuffix((".jpg", ".png")) should > return "asdf.jpg", not "asdf".)
There's a slight problem with that: what happens if more than one suffix matches? E.g. given:
"musical".lcut(('al', 'ical'))
should the suffix "al" be removed, leaving "music"? (First match wins.)
Or should the suffix "ical" be removed, leaving "mus"? (Longest match wins.)
I don't think we can decide which is better, and I'm not keen on a keyword argument to choose one or the other, so I suggest we stick to the 90% solution of only supporting a single suffix.
We can always revisit that in the future.