My take on Multiplicative Persistence, inspired by this Numberphile video: https://www.youtube.com/watch?v=Wim9WJeDTHQ

mult_persistence.py

from functools import reduce

def per(n):
    k = 0 # k is the persistence
    
    def per_rec(n, k):
        digits = [int(c) for c in str(n)]
        
        if len(digits) == 1:
            print('persistence ' + str(k))
        
        # with functools
        new_n = reduce(lambda x, y: x * y, digits)
        
        # without functools, if you will
        #new_n = 1
        #for x in digits:
        #    new_n *= x
        
        print('%s = %d' % (' * '.join([d for d in str(n)]), new_n))
    
        per_rec(new_n, k + 1)
    
    per_rec(n, k)