用Python实现求最大公约数和判断是否是素数

程序如下:#！/usr/bin/env pythondef showMaxFactor（num）:
count = num / 2
while count > 1:
if num % count == 0:
print "largest factor of %d is %d" % （num, count）
break #break跳出时会跳出下面的else语句
count -= 1
else:
print num, "is prime"for eachNum in range（10,21）:
showMaxFactor（eachNum）输出如下: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