Tests if a number is a prime number or not

testifprime.py

num = int(input('input a number: '))
lst = range(2, 1000)
la = []

for x in lst:
    if x < num and x != num and x != 0 and num % x == 0:
            la.append(x)

if la == []:
    print('number ' + str(num) + ' is a prime number')
else:
    print('number ' + str(num) + ' is NOT a prime number')