import random
checkcode = ‘‘
for i in range(4):
current = random.randrange(0, 4)
if current != i:
temp = chr(random.randint(65, 90))
else:
temp = random.randint(0, 9)
checkcode += str(temp)
print(checkcode)
原文：https://www.cnblogs.com/hamao/p/10808445.html