Question

Possible Duplicate:
Python reverse / inverse a mapping

Say I have the following.

D = {'a':1,'b':2,'c':3}

How would I reverse each element so I get

inverseD = {1:'a',2:'b',3'c'}

Answer 1

use a dict comprehension (Python 2.7+ and 3.0+):

D = {'a':1,'b':2,'c':3}
inverse = {v: k for k, v in D.items()}
print(inverse)
# {1: 'a', 2: 'b', 3: 'c'}