List creation and return in Function

[leoahum]

def factors(x):
   L = []
   for i in range(1, x + 1):
       if x % i == 0:
            L.append(i)
    return L


num = 84


print (factors(num))

I'm trying to return a list in this function. Python gives me an error "IndentationError: unindent does not match any outer indentation level"

Could someone help me fix it? Many thanks in advance!