go through each number between 1 and the number input until it finds a factor and adds it to a list

Question

def factorList(num):
    listOfFactors = []
    for i in range <= num:
        if num / i == 0:
            listOfFactors.append(i)
    print(listOfFactors)  
factorList(36)

I want the function to go through each number between 1 and the number input until it finds a factor and adds it to a list

https://docs.python.org/3.10/library/functions.html#func-range — chepner, Sep 14 '22 at 21:27
`for i in range(num):`. I can't believe this isn't in dozens of tutorials. — Barmar, Sep 14 '22 at 21:27
Some old post for reference - https://stackoverflow.com/questions/6800193/ faster way to find factors... — Daniel Hao, Sep 14 '22 at 21:42

score 2 · Accepted Answer · answered Sep 14 '22 at 21:29

range() is a function (it needs parens), and it starts at zero, rather than 1...

You seem to have tried to combine range with a while loop logic, like so

i = 1
while i <= num:
  # if ... append ... 
  i += 1

But you can do the same with list-comprehension

def factorList(num):
    return [i for i in range(1, num+1) if num % i == 0]

print(factorList(36))

Output

[1, 2, 3, 4, 6, 9, 12, 18, 36]

side-note: For factorization, you only need to loop up to the square-root of the number.

score 1 · Answer 2 · answered Sep 14 '22 at 21:28

1

range() is a function that returns a sequence of numbers, so you need to call it like a function.

for i in range(num):

See some documentation here: https://www.w3schools.com/python/ref_func_range.asp

answered Sep 14 '22 at 21:28

Emily Bernstein

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go through each number between 1 and the number input until it finds a factor and adds it to a list

2 Answers2