MNT add pyarrow dependency

[adrinjalali]

Fixes #1334

[hildeweerts]

It does look like they're still gathering feedback before the pyarrow dependency becomes final (but perhaps the actual decision has already been taken?).

I haven't read the entire thread but a couple of comments stood out to me. One major thing to consider is that the pyarrow build is pretty big:

Including PyArrow would naturally increase the installation size of pandas. For example, installing pandas and PyArrow using pip from wheels, numpy and pandas requires about 70MB, and including PyArrow requires an additional 120MB. An increase of installation size would have negative implication using pandas in space-constrained development or deployment environments such as AWS Lambda.

And this one.

Also, if PyArrow is truly going to be a required required dependency in Pandas 3.0, then I don't see the point of the current DeprecationWarning in pandas 2.2.0. All sane package python managers install required dependencies automatically, so users don't need to take any action anyway.

[adrinjalali]

Yes, they have already voted and made the decision. I've been watching this for quite some time now. It's happening. My recommendation to people is simply to switch to polars.

[adrinjalali]

oh, I was gonna fix other issues, I'll open a new PR for them then.