Deprecate `codecs.open()`

[methane]

Discussion: https://discuss.python.org/t/deprecating-codecs-open/88135/

codecs.open() is used a lot because it was recommended in Python 2.
But open() (or io.open()) is recommended since Python 3.

It is a time to deprecate codecs.open().
Since it is still widely used, we won't schedule its removal.

Linked PRs

• gh-133036: Deprecate codecs.open #133038

[ngoldbaum]

I don't know if this deserves a better clarification in the deprecation notice, but I hit a corner case that took me a few minutes to understand today. Perhaps commenting here will help someone else.

I tried replacing codecs.open with open in a spot in pandas and hit this error:

>               with open(as_json, "wb", encoding="utf8") as f:
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
E               ValueError: binary mode doesn't take an encoding argument

I fixed it by replacing "wb" with "w". It seems codecs.open is a little more permissive here than open.