[Python-ideas] Give regex operations more sugar

[Chris Angelico]

On Thu, Jun 14, 2018 at 8:54 AM, MRAB <python at mrabarnett.plus.com> wrote:
> On 2018-06-13 21:52, Chris Angelico wrote:
>>
>> On Thu, Jun 14, 2018 at 6:43 AM, Michel Desmoulin
>> <desmoulinmichel at gmail.com> wrote:
>>>
>>>
>>>
>>> Le 13/06/2018 à 19:11, Mike Miller a écrit :
>>>>
>>>>
>>>> On 2018-06-13 06:33, Michel Desmoulin wrote:
>>>>>
>>>>>
>>>>> I often wished for findall and sub to be string methods, so +1 on that.
>>>>>
>>>>
>>>> Agreed, and there are a few string functions that could be extended (to
>>>> take a sequence) to handle more cases that push folks to regex, perhaps
>>>> earlier than they should.
>>>
>>>
>>> str.replace come to mind. It's a annoying to have to chain it 5 times
>>> while we could pass optionally a tuple.
>>
>>
>> That would be handy. Either pass two sequences of equal length
>> (replace each with the corresponding), or one sequence and one string
>> (replaceactual any with that). (And yes, I know that a string IS a
>> sequence.) This would want to be semantically different from chained
>> calls, in that a single replace([x,y,z], q) would avoid re-replacing;
>> but for many situations, it'll be functionally identical.
>>
> Would it check first-to-last or longest-to-shortest? I think that
> longest-to-shortest would be the most useful.
>
>>>> old = ('cat', 'cats')
>>>> new = ('mouse', 'mice')
>>>>
>>>> # First-to-last.
>>>> 'cats'.replace(old, new)
> 'mouses'
>>>>
>>>> # Longest-to-shortest.
>>>> 'cats'.replace(old, new)
> 'mice'

I'd go first-to-last, personally. You can always sort them by length
if you want that behaviour. But that's a bikeshed where I'm not too
picky about the colour.

ChrisA