>>> d = dict(zip(['key1', 'key2'], [[]]*2))
>>> d
{'key2': [], 'key1': []}
>>> d['key1'].append(1)
>>> d
{'key2': [1], 'key1': [1]}
>>> d = dict(zip(['key1', 'key2'], [[], []]))
>>> d
{'key2': [], 'key1': []}
>>> d['key1'].append(1)
>>> d
{'key2': [], 'key1': [1]}
>>>