prime/prime.py

   1 #!/usr/bin/python
   2 #
   3 # Check if a number is prime (brute force)
   4 #
   5 # Luiz Fernando N. Capitulino
   6 # <lcapitulino@gmail.com>
   7
   8 from sys import exit, stdout, argv
   9
  10 def is_prime(num):
  11         "Check if a number is prime (brute force)"
  12         if num < 2:
  13                 return False
  14
  15         for i in range(2, num):
  16                 if not (num % i):
  17                         return False
  18         return True
  19
  20 def main():
  21         if len(argv) != 2:
  22                 stdout.write('Usage: prime < number >\n')
  23                 exit(1)
  24
  25         num = int(argv[1])
  26         if is_prime(num):
  27                 print 'is prime'
  28                 exit(1)
  29         else:
  30                 print 'is not prime'
  31                 exit(0)
  32
  33 if __name__ == "__main__":
  34         main()