Feature request: handle NaN

[bersbersbers]

What did you do?

import humanize, math
humanize.metric(math.nan)

What did you expect to happen?

"NaN"

What actually happened?

Traceback (most recent call last):
File "", line 1, in
File "C:\Users\bers\.pyenv-win-venv\envs\project\lib\site-packages\humanize\number.py", line 519, in metric
exponent = int(math.floor(math.log10(abs(value)))) if value != 0 else 0
ValueError: cannot convert float NaN to integer

[bersbersbers]

(For the record, I did not actually do humanize.metric(math.nan), I just happened to come across a NaN value.)

[hugovk]

Thanks for the report, PR welcome to fix it!

[bersbersbers]

It would also make sense to handle this in one common location for +/-Inf and all other functions failing on NaN, such as humanize.scientific(math.nan) or humanize.fractional(math.nan).