feat[python] support units for estimated_size ("mb","gb", etc)

[alexander-beedie]

Added convenience support for returning estimated_size() in the units of your choice (default remains bytes):

Examples:

# integrated with series...
series.estimated_size("kb")
series.estimated_size("mb")

# ...and dataframe
frame.estimated_size("gb")
frame.estimated_size("tb")

[stinodego]

Nice utility, but shouldn't we try to implement these things on the Rust side? I'd rather keep our Python bindings as skinny as possible.

[ritchie46]

Nice utility, but shouldn't we try to implement these things on the Rust side? I'd rather keep our Python bindings as skinny as possible.

I sometimes argue the other way, as in Rust we have to pay with compile times and binary size. I think rust users are fine with dealing with bytes, and I don't think it is worth an extra enum on the rust side.

If rust compiled fast, I certainly agreed with you.

[alexander-beedie]

I think rust users are fine with dealing with bytes, and I don't think it is worth an extra enum on the rust side.

Pretty much my thoughts; you're only likely to want to change the units when interactively eyeballing a frame in python, rather than wanting to compile a unit-scaled float (vs the usual bytes integer in Rust).

[ritchie46]

Thanks @alexander-beedie and thanks for the review @stinodego .