merge dict in python

gistfile1.py

>>> x = {'a': 1, 'b': 2}
>>> y = {'b': 10, 'c': 11}
>>> z = dict(x.items() + y.items())
>>> z
{'a': 1, 'c': 11, 'b': 10}
>>> z = dict(x, **y)
>>> z
{'a': 1, 'c': 11, 'b': 10}