CLN: remove have_pytz?

[jbrockmendel]

From tslib.pyx

try:
    import pytz
    UTC = pytz.utc
    have_pytz = True
except:
    have_pytz = False

[...]
def tz_convert_single(int64_t val, object tz1, object tz2):
    [...]
    if not have_pytz:
        import pytz

From much earlier in tslib.pyx

from pytz.tzinfo import BaseTzInfo as _pytz_BaseTzInfo

Is the try/except still necessary? If so, is import pytz the right thing to do in tz_convert_single?

[gfyoung]

Reminds me of #17173. We wouldn't deprecated anything but just remove the check if it is no longer necessary, but I suspect a more involved solution will be needed @jreback ?

[chris-b1]

pytz is a hard dependency so I think this could simply be removed.

[jbrockmendel]

We wouldn't deprecated anything but just remove the check

Note to self: learn the difference between "deprecate" and "remove".

If there's a consensus, I'll make a PR to remove this check. While we're at it, do we still need to check for dateutil versions?

[gfyoung]

@jbrockmendel : #17002 might be relevant for this. I would refrain from this for the moment, but you can give it a shot in a separate commit to see.

[jbrockmendel]

There are also several try/excepts in src/inference.pyx for importing dateutil.parser

[jreback]

pytz is a strict requirement, so this could be removed.