4 # The algorithm is not efficient, but easy to understand.
5 # If there are large factors, it will take forever to find them,
6 # because we try all odd numbers between 3 and sqrt(n)...
13 raise ValueError('fact() argument should be >= 1')
15 return [] # special case
17 # Treat even factors special, so we can use i += 2 later
21 # Try odd numbers up to sqrt(n)
39 source
= iter(input, '')
44 print(arg
, 'is not an integer')
48 if __name__
== "__main__":