Prime factors of number
The list of prime factors of a number is a list of prime numbers that multiply together to give the original number. You can find the list of prime factors of a number using a simple Python function.
All you really need is a while
loop to iterate over all possible prime factors, starting with 2
. If the current factor
exactly divides num
, you can add factor
to the factors
list and divide num
by factor
. Otherwise, you can increment factor
by one.
def prime_factors(num): factors = [] factor = 2 while (num >= 2): if (num % factor == 0): factors.append(factor) num = num / factor else: factor += 1 return factors prime_factors(12) # [2,2,3] prime_factors(42) # [2,3,7]