Python dictionary.keys() error

Python 3 changed the behavior of dict.keys such that it now returns a dict_keys object, which is iterable but not indexable (it’s like the old dict.iterkeys, which is gone now). You can get the Python 2 result back with an explicit call to list:

>>> b = { 'video':0, 'music':23 }
>>> k = list(b.keys())
>>> k
['music', 'video']

or just

>>> list(b)
['music', 'video']