示例一：
AGE = 20
count = 0
while True:
if count == 5:
break
GUESS = int(input("AGE:"))
if GUESS == AGE :
print("It is right!")
break
elif GUESS > AGE :
print("It is bigger!")
else:
print("It is small!")
count +=1
if count == 5:
print("You hava tried too many times!")
示例二：
_user="root"
_passwd="okooo123"
count = 0
while count<3:
username = input("user:")
passwd = input("passwd:")
if _user == username and _passwd == passwd:
print("Welcome")
break
elif _user != username or _passwd !=passwd:
print("username or password is wrong")
count +=1
else:
print("Too many times wrong !")
示例三：
user = "root"
count =0
while count <5:
Guess = input("user:")
if Guess == user:
print("It is right!")
break
elif Guess != user:
print("It is wrong!")
count +=1
else:
print("You input were wrong!")上面的三个示例均可实现while循环的基本知识，建议使用示例二的写法。
