Question

Lets say I have two dictionaries:

a = {'a': 1, 'b': 2, 'c': 3}
b = {'b': 2, 'c': 3, 'd': 4, 'e': 5}

What’s the most pythonic way to find the non mutual items between the two of them such that for a and b I would get:

{'a': 1, 'd': 4, 'e': 5}

I had thought:

{key: b[key] for key in b if not a.get(key)}

but that only goes one way (b items not in a) and

a_only = {key: a[key] for key in a if not b.get(key)}.items()
b_only = {key: b[key] for key in b if not a.get(key)}.items()

dict(a_only + b_only)

seams very messy. Any other solutions?

Answer 1

>>> dict(set(a.iteritems()) ^ set(b.iteritems()))
{'a': 1, 'e': 5, 'd': 4}