Find all the divisors of a number using Python

Question

I am trying to write a Python script that will find prime numbers. In the way that I am going about this, the script is going to take a number from a range, determine the factors, determine if the only two factors are 1 and itself, and return true if it's a prime number. I need help with my code to find the factors.

num = int(input("enter: "))

i = 1

while i < num:
  if num % i == 0:
    print(i)
    i += 1
  else:
    pass

The i is set to 1 because you can't divide by 0. However, the return starts to work, however, it only returns a couple of numbers, not the full list that I am hoping for. For example, you input 20, it returns only 1 and 2.

Answer 1

You're only incrementing i in the "is even" case. This'd fix it:

num = int(input("enter: "))

i = 1

while i < num:
  if num % i == 0:
    print(i)
  i += 1

However, it's better to use range() for iterating over a range of numbers:

num = int(input("enter: "))
for i in range(1, num):
  if num % i == 0:
    print(i)