Invert-a-dict X59451

A dictionary is said to be invertible if all keys are associated to a different value (and thus, each value happens only once).

Program a function inverse(d) that given an invertible dictionary d with string keys and int values, returns its inverse. That is, a dictionary where each int value in the original dictionary is now a key, and its string key in the original dictionary is now its associated value.

For instance, if the original dictionary d is:

{ 'hello' : 3,
  'bye' : 5,
  'someone' : 1 }

the function will return

{ 3: 'hello',
  5: 'bye',
  1: 'someone' }

The function does not have to deal with non-invertible dictionaries. The received dictionary will always be invertible.

Observation

Only the function will be evaluated. If your submission includes a main program (e.g. with testmod), it must be either commented out or inside a condition if __name__ == ’__main__’