pyschools Topic 5: Question 12题目：分解质因素
Given a positive integer, write a function that computes the prime factors that can be multplied together to get back the same integer.
def primeFactorization(num):
factor=[]
while num>1:
for i in range(2,num+1):
if num%i==0:
factor.append(i)
num = num//i
break
return factor
