Python Prime Numbers Code Problem
You don't get an empty list. See this. However you won't get the desired results because in python int divided by int is always int.  You may want to try this:

import math

factor_list = [ ]

def integer_test(x):

    if math.floor(x) == math.ceil(x):
        return True
    else:
        return False

def factor_checker(x):

    count = 0
    y = x
    while count &lt;= y:
        print(count)
        count += 1
        if integer_test(1.0 * x / count) == True:
            factor_list.append(count)

factor_checker(45)

print(factor_list)


In this code x/count is a double. So the integer_test will only return true if it's ceiling and floor return the same number i.e the integer itself.