Simple solution using itertools that preserves order (latter dicts have precedence)
import# py2
from itertools asimport itchain, imap
merge = lambda *args: dict(it.chain.from_iterable(it.imap(dict.iteritems, args)))
# py3
from itertools import chain
merge = lambda *args: dict(chain.from_iterable(map(dict.items, args)))
And it's usage:
>>> x = {'a':1, 'b': 2}
>>> y = {'b':10, 'c': 11}
>>> merge(x, y)
{'a': 1, 'b': 10, 'c': 11}
>>> z = {'c': 3, 'd': 4}
>>> merge(x, y, z)
{'a': 1, 'b': 10, 'c': 3, 'd': 4}