Comparing two dictionaries and checking how many (key, value) pairs are equal
If you want to know how many values match in both the dictionaries, you should have said that :)
Maybe something like this:
shared_items = {k: x[k] for k in x if k in y and x[k] == y[k]}print len(shared_items)
What you want to do is simply x==y
What you do is not a good idea, because the items in a dictionary are not supposed to have any order. You might be comparing [('a',1),('b',1)]
with [('b',1), ('a',1)]
(same dictionaries, different order).
For example, see this:
>>> x = dict(a=2, b=2,c=3, d=4)>>> x{'a': 2, 'c': 3, 'b': 2, 'd': 4}>>> y = dict(b=2,c=3, d=4)>>> y{'c': 3, 'b': 2, 'd': 4}>>> zip(x.iteritems(), y.iteritems())[(('a', 2), ('c', 3)), (('c', 3), ('b', 2)), (('b', 2), ('d', 4))]
The difference is only one item, but your algorithm will see that all items are different
def dict_compare(d1, d2): d1_keys = set(d1.keys()) d2_keys = set(d2.keys()) shared_keys = d1_keys.intersection(d2_keys) added = d1_keys - d2_keys removed = d2_keys - d1_keys modified = {o : (d1[o], d2[o]) for o in shared_keys if d1[o] != d2[o]} same = set(o for o in shared_keys if d1[o] == d2[o]) return added, removed, modified, samex = dict(a=1, b=2)y = dict(a=2, b=2)added, removed, modified, same = dict_compare(x, y)