41: Moved executed code to 'main' section.

problem41.py

-from itertools import permutations
-
 def is_prime(n):
     if n == 2:
         return True
@@ -13,13 +11,16 @@ def is_prime(n):
 
     return True
 
-m = 0
+if __name__ == '__main__':
+    from itertools import permutations
+
+    m = 0
 
-for i in xrange(2, 10):
+    for i in xrange(2, 10):
         for digits in permutations(map(str, range(i, 0, -1))):
             n = int(''.join(digits))
 
             if n > m and is_prime(n):
                 m = n
 
-print m
+    print m