[Python-ideas] Give regex operations more sugar

[Franklin? Lee]

On Wed, Jun 13, 2018 at 8:15 PM, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> Chris Angelico wrote:
>>
>> This would want to be semantically different from chained
>> calls, in that a single replace([x,y,z], q) would avoid re-replacing;
>
>
> +1, this would be REALLY handy!
>
> It's easy to trip yourself up with chained replacements
> if you're not careful -- like I did once when escaping
> things using &xxx; sequences in XML. If you don't do it
> in the right order, you end up escaping some of the &s
> you just inserted. :-(
>
> --
> Greg

In a thread earlier this year, I suggested allowing a dict:
https://mail.python.org/pipermail/python-ideas/2018-February/048875.html

For example:
    txt.replace({
            '&': '&',
            '"': '"',
            "'": ''',
            ...
        })

Tuples of strings can be dict keys, so it's also possible to allow
several options to be replaced with a single thing.

One use I had for multi-replace was to parse a file that was almost
CSV, but not close enough to be parsed by `import csv`. I had to be
careful to get the order right so that old replacements wouldn't cause
newer ones.