99 problems - python - 36

Determine the prime factors of a given positive integer.

Construct a list containing the prime factors and their multiplicity.

Example:

* (prime-factors-mult 315)
((3 2) (5 1) (7 1))

#using prime_factors from the previous problem
import itertools
def prime_factors_mult(n):
    return [(x, len(list(y))) for x,y in itertools.groupby(prime_factors(n))]