Python實現求最大公約數及判斷素數的方法

#!/usr/bin/env python 
def showMaxFactor(num): 
 count = num / 2 
 while count > 1: 
 if num % count == 0: 
 print 'largest factor of %d is %d' % (num, count) 
 break #break跳出時會跳出下面的else語句 
 count -= 1 
 else: 
 print num, "is prime" 
for eachNum in range(10,21): 
 showMaxFactor(eachNum) 

largest factor of 10 is 5
11 is prime
largest factor of 12 is 6
13 is prime
largest factor of 14 is 7
largest factor of 15 is 5
largest factor of 16 is 8
17 is prime
largest factor of 18 is 9
19 is prime
largest factor of 20 is 10