On 2/18/2016 12:59 AM, Ben Finney wrote:
Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> writes:Today I learned that **kwargs style keyword arguments can be any string: py> def test(**kw): ... print(kw) ... py> kwargs = {'abc-def': 42, '': 23, '---': 999, '123': 17} py> test(**kwargs) {'': 23, '123': 17, '---': 999, 'abc-def': 42} Bug or feature?Incidental feature, I think.
The was discussed on pydev some years ago. Guido says leave as is. This and similar cases of allowing non-identifier is string-dicts does not seem to cause a problem and apparently has a few rare legitimate usages.
If the caller is deliberately unpacking a dict, it's on them to ensure the keys are valid identifiers or wear the consequences. If the function cares so little about the keys in its kwargs that (as in your example) any string will do for each key, then it's a consenting actor IMO. The times when it's a problem – i.e. that the function is trying to use items from that dictionary as name bindings – the errors will be raised to the caller that unpacked that mapping. That's where the errors belong.
-- Terry Jan Reedy -- https://mail.python.org/mailman/listinfo/python-list
