Python - intersection between a list and keys of a dictionary

Question

I have a list that looks like this:

l1 = [\'200:200\', \'90:728\']

I have a dictionary that looks like this:

d1 = {\'200:20         


        

Answer 1

Define efficient. Anyway here's what I would do. If it was too slow I'd probably move it to Cython.

s1 = set(l1)
s2 = set(d1.keys())
s3 = s1 & s2
# now you can access d1 using only keys in s3, or construct a new dict if you like
d2 = dict([(k,d1[k]) for k in s3])