Not sure if this is predicted behaviour, but if I make a dict like:

>>> x = {0: 'bar', True: 'foo'}

and modify True with 1, or 0 with False:
>>> x[False] = 'boo'
>>> x[1] = 'far'

the modifications happen:
>>> x
{0: 'boo', True: 'far'}

Is this expected behaviour? It seems that the hashes for 'False' and 0 are confused, as are the hashes for 'True' and 1.

Thanks for the report.  Yes, this is expected.  Dictionary membership is based on equality of keys.  Since True and 1 are equal, only one of them can be present in a dictionary at a time (and a key lookup works with either).

>>> x = {0: 'bar'}
>>> x[0]
'bar'
>>> x[False]
'bar'
>>> x[0.0]
'bar'
>>> 0 == False
True

Ahh, I see. You are correct. Thanks.