prompt> ./eratosthenes.py 100
[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]
prompt> ./eratosthenes.py 97
[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89]
prompt> 

prompt> cat isprime.py 
#!/usr/bin/python

import sys

def isprime( n ):
  return len( filter(lambda m: n%m==0, range(2,n))) == 0

if isprime( int(sys.argv[1]) ) :
  print sys.argv[1] + " is a prime number."
else:
  print sys.argv[1] + " is not a prime number."

prompt> ./isprime.py 98
98 is not a prime number.
prompt> ./isprime.py 97
97 is a prime number.
prompt>