Divide the values of two dictionaries in python

Question

I have two dictionaries with the same keys and I would like to do division on the values to update or create a new dictionary, keeping the keys intact, with the quotient as

Answer 1

Using viewkeys (python2.7):

{k: float(d2[k])/d1[k] for k in d1.viewkeys() & d2}

Same in python 3 (where we can drop the float() call altogether):

{k: d2[k]/d1[k] for k in d1.keys() & d2}

Yes, I am using a key intersection here; if you are absolutely sure your keys are the same in both, just use d2:

{k: float(d2[k])/d1[k] for k in d2}

And to be complete, In Python 2.6 and before you'll have to use a dict() constructor with a generator expression to achieve the same:

dict((k, float(d2[k])/d1[k]) for k in d2)

which generates a sequence of key-value tuples.