Python dict merging

dict_merge.py

a = { "a": 5, "b": 5 }
b = { "c": 5, "d": 5 }
c = { **a, **b }
assert c == { "a": 5, "b": 5, "c": 5, "d": 5 }
# order matters!
# the last added will overwrite the first added
c = { **a, **b, "a": 10 }
assert c == { "a": 10, "b": 5, "c": 5, "d": 5 }
b["a"] = 10
c = { **a, **b }
assert c == { "a": 10, "b": 5, "c": 5, "d": 5 }
# this doesn't work when initializing with dict(...)
c = dict(**a, **b)
# => TypeError: type object got multiple values for keyword argument 'a'