Is it reasonable to use None as a dictionary key in Python?

Question

None seems to work as a dictionary key, but I am wondering if that will just lead to trouble later. For example, this works:

>>> x={\'a\':1, \'b\':2, N         


        

Answer 1

You want trouble? here we go:

>>> json.loads(json.dumps({None:None}))
{u'null': None}

So yea, better stay away from json if you do use None as a key. You can patch this by custom (de/)serializer, but I would advise against use of None as a key in the first place.