[Python-Dev] dict __contains__ raises TypeError on unhashable input

Ethan Furman ethan at stoneleaf.us
Sat Jul 20 03:30:23 CEST 2013


http://bugs.python.org/issue18510

Commenting further:

     some_key in dict

is conceptually the same as

     some_key in dict.keys()

which /would/ return False for an unhashable key -- at least it did in 2.x; for 3.x you have to say

     some_key in list(dict.keys())

which seems like a step backwards.

Is it worth changing __contains__ and keys() to be in line with equality?

--
~Ethan~


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