10 Sep
2013
10 Sep
'13
12:25 p.m.
On 10 September 2013 13:24, Paul Moore
On 10 September 2013 13:00, Nick Coghlan
wrote: Is this just syntactic sugar for recursive lookup of a transformed version in __missing__? Or a way of supplying a custom "key" function to a dictionary?
Not quite, because the dict should preserve the originally entered key.
td['FOO'] = 42 td['bar'] = 1 td['foo'] 42 td['BAR'] 1 list(td.keys()) ['FOO', 'bar']
This actually prompts the question, what should the following produce:
td['FOO'] = 42 td['foo'] = 32 list(td.keys())
['FOO'] or ['foo']? Both answers are justifiable. Both are possibly even useful depending on context...
I'm using the case where the transform is str.lower here - sorry I wasn't explicit. Paul