示例：
age_of_oldboy = 56
count = 0 while True:
if count == 3:
#只能尝试三次
break
guess_age = int(input("guess age:"))
if guess_age == age_of_oldboy :
print("yes,you got it.")
break # 猜对就跳出循环
elif guess_age > age_of_oldboy:
print("think smaller...") #给第二种可能，不是就有可能
else:
print("think bigger!")
count += 1
示例2：
age_of_oldboy = 56
count = 0 while count < 3:#简洁写法，还是最多循环三次
guess_age = int(input("guess age:"))
if guess_age == age_of_oldboy :
print("yes,you got it.")
break
# 猜对就跳出循环
elif guess_age > age_of_oldboy:
print("think smaller...")
#给第二种可能，不是就有可能
else:
print("think bigger!")
count += 1
if count == 3:
countine_confirm = input("do you want keep guessing?")#这4行是可以询问是否继续
if countine_confirm != ‘n‘:
count = 0
else:
print("you have tried too many times..")
while循环
原文：http://www.cnblogs.com/FutureStar/p/7657117.html
