n = int(input("Enter a number : "))
a = [1, n]
fac = 2
while fac <= n/2:
if n % fac == 0:
a.append(fac)
fac += 1
print(a)
A simple code to print the factors of a number.
change your code like this
if n % fac == 0:
a.append(fac)
fac += 1