Jacob Holm wrote:
On 2011-06-15 02:28, Jan Kaliszewski wrote:
-- 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).
I disagree. One of the main selling points of this feature for me is that adding a few "hidden parameters" to a function does not change the signature of the function. If you raise a TypeError when the name of a hidden parameter is in kwargs this is a change in signature.
This is another reason why function parameters should not be used for something that is not a function parameter! +1 on the ability to inject locals into a function namespace. -1 on having the syntax for that masquerade as function arguments. -- Steven