old_contents: # Naive implementation of the
  # Sieve of Eratosthenes
  
  end = 1000000;
  sieve = [None] * end;
  count = 0;
  
  for i in xrange(2, end):
      if sieve[i] is None:
  	for j in xrange(2*i, end, i):
              sieve[j] = 1;
          count+= 1;
  
  print "There are", count, "prime numbers under", end
  
new_contents: # Naive implementation of the
  # Sieve of Eratosthenes
  import sys
  
  end = int(sys.argv[1])
  sieve = [None] * end
  count = 0
  
  for i in xrange(2, end):
      if sieve[i] is None:
  	for j in xrange(2*i, end, i):
              sieve[j] = 1
          count+= 1
  
  print "There are", count, "prime numbers under", end
  
subject: Make pythons sieve implementation more pythonic