1，while

檢測(cè)輸入的值 是否合適的，while簡(jiǎn)單應(yīng)用。

_age = 30
count = 0
total = 3
while count < total:
    age = int(input("guess age : "))
    if _age < age:
        print("it's larger")
    elif _age == age:
        print("you got it")
        break
    else:
        print("it's smaller")

    count += 1
    if total - count > 0:
        print("you  already left %d times" % (total - count))
else:
    print("you have already used all your chance, Bye"

or 不帶else的常規(guī)用法

_age = 30
count = 0
total = 3
while count < total:
    age = int(input("guess age : "))
    if _age < age:
        print("it's larger")
    elif _age == age:
        print("you got it")
        break
    else:
        print("it's smaller")

    count += 1
    if total - count > 0:
        print("you  already left %d times" % (total - count))

2,for
for循環(huán)的用法

for i in range(0,10,2):
    print(i)

_age = 2

count = 0
total = 3

for i in  range(3):
    age = int(input("guess age : "))
    if _age < age:
        print("it's larger")
    elif _age == age:
        print("you got it")
        break
    else:
        print("it's smaller")

    if total - i-1 > 0:
        print("you  already left %d times" % (total - count))
else:
    print("you have already used all your chance, Bye")