[Python-ideas] 'Injecting' objects as function-local constants

Jan Kaliszewski zuo at chopin.edu.pl
Wed Jun 15 02:28:25 CEST 2011

Jan Kaliszewski dixit (2011-06-14, 12:17):

> It's obvious that such a repetition must be prohibited (SyntaxError, at
> compile time):
>     def sth(my_var, **, my_var): "do something"

Of course, I ment:
      def sth(my_var, **, my_var='foo'): "do something"

> But in case of:
>     def sth(*args, **kwargs, my_var='foo'): "do something"
> -- should 'my_var' in kwargs be allowed? (it's a runtime question)
> There is no real conflict here, so at the first sight I'd say: yes. 

On second thought: no, such repetitions also should *not* be allowed.
If a programmer, by mistake, would try to specify the argument value in
a call, an explicit TypeError should be raised -- otherwise it'd become
a trap (especially for beginners and absent-minded programmers).


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