feat(python): allow use of Config object as a function decorator

[alexander-beedie]

A nice usability trick I picked up recently; transparent use of context managers as function decorators. Allows for the application of specific Config options to be scoped to the duration of a given function:

Examples

@pl.Config( set_ascii_tables=True )
def write_ascii_frame_to_stdout( df: pl.DataFrame ) -> None:
    sys.stdout.write( str(df) )

@pl.Config( verbose=True )
def do_various_things():
    ...

[erinov1]

This would be really nice to have for StringCache as well!

[alexander-beedie]

This would be really nice to have for StringCache as well!

@erinov1: you read my mind... :)
Done - #9309

[ritchie46]

That's really nice! So this only gets activated on function call?

Just read about the https://docs.python.org/3/library/contextlib.html#contextlib.ContextDecorator. Nice stuff!