[Python-ideas] Add list.join() please

Chris Barker - NOAA Federal chris.barker at noaa.gov
Wed Jan 30 00:43:56 EST 2019

> Alex Shafer via Python-ideas wrote:
>> 1) I'm in favor of adding a stringify method to all collections
> Are you volunteering to update all the collection
> classes in the world written in Python? :-)

To be fair, we could add an implementation to the sequence ABC, and
get pretty far.

Not that I’m suggesting that — as I said earlier, Python is all about
iterables,  not sequences, anyway.

Also, despite some folks’ instance that this “stringify’ method is
something many folks want -.I’m not even sure what it is.

I was thinking it was:

def stringify(self, sep):
     return sep.join(str(i) for i in self)

Which, by the way would work for any iterable :-)

If you want a language designed specifically for text processing, use Perl.

Python is deliberately strongly typed, so that:

2 + “2”

Raises an error. Why should:

“”.join([2, “2”]) not raise an error as well?

And aside from repr or ascii, when I turn numbers into text, I usually
want to control the formatting anyway:

“ “.join(f”{n:.2f}” for n in seq)

So having str() called automatically for a join wouldn’t be that useful.


More information about the Python-ideas mailing list