I have two dictionaries, but for simplification, I will take these two:
>>> x = dict(a=1, b=2)
>>> y = dict(a=2, b=2)
Now, I want to compare whether each key, value pair in x has the same corresponding value in y. So I wrote this:
>>> for x_values, y_values in zip(x.iteritems(), y.iteritems()):
if x_values == y_values:
print 'Ok', x_values, y_values
else:
print 'Not', x_values, y_values
And it works since a tuple is returned and then compared for equality.
My questions:
Is this correct? Is there a better way to do this? Better not in speed, I am talking about code elegance.
UPDATE: I forgot to mention that I have to check 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