接續上次的代碼，是不是只有執行一次才就結束，想要再繼續猜，就要在執行一次，是不是有點挺麻煩的？

所以這次我們就來再多做一點點功能進去，讓代碼可以多次循環地執行代碼，Go....

首先，我們先來了解一下，簡單的 while循環 怎麼寫

#!/usr/bin/env python3

# -*- coding:utf-8 -*-

count = 0

while True:

    print("count:", count)

    count += 1

---------------執行結果---------------

count: 70937

count: 70938

count: 70939

count: 70940

count: 70941

count: 70942

count: 70943

count: 70944

上面的代碼是一個簡單的 while循環 ，這是一個無限的迴圈，只要while為真，就會一直執行不會中斷，需要由使用者自行中斷，

簡單的會了，我們開始來結合上次的代碼

#!/usr/bin/env python3

# -*- coding:utf-8 -*-

age_of_ironman = 35

while True:

    guess_age = int(input("guess age:"))

    if guess_age == age_of_ironman:

        print("Bingo, You got it!!!")

    elif guess_age > age_of_ironman:

        print("You may think smaller...")

    else:

        print("You may think bigger...")

---------------執行結果---------------

guess age:23

You may think bigger...

guess age:98

You may think smaller...

guess age:84

You may think smaller...

guess age:35

Bingo, You got it!!!

guess age:

咦~有發現什麼不尋常的地方嗎？沒錯，即使你輸入正確了，這遊戲也不會結束，所以我們要在新增一個可以結束遊戲的條件，

要怎麼結束呢？ 這時候我們必須在代碼中加入 break 就可以了，再修改一下代碼

#!/usr/bin/env python3

# -*- coding:utf-8 -*-

age_of_ironman = 35

while True:

    guess_age = int(input("guess age:"))

    if guess_age == age_of_ironman:

        print("Bingo, You got it!!!")

        break

    elif guess_age > age_of_ironman:

        print("You may think smaller...")

    else:

        print("You may think bigger...")

---------------執行結果---------------

guess age:39

You may think smaller...

guess age:28

You may think bigger...

guess age:59

You may think smaller...

guess age:39

You may think smaller...

guess age:35

Bingo, You got it!!!

Process finished with exit code 0

這樣又達成目的了，可是我們想要限制這個遊戲猜只能猜三次，三次猜不中就退出遊戲，該怎麼寫呢？

這時候就需要一個計數器來協助完成這次的任務，所以再為代碼稍稍加強一下功能

#!/usr/bin/env python3

# -*- coding:utf-8 -*-

age_of_ironman = 35

count = 0

while True:

    if count >= 3:

        break

    guess_age = int(input("guess age:"))

    if guess_age == age_of_ironman:

        print("Bingo, You got it!!!")

        break

    elif guess_age > age_of_ironman:

        print("You may think smaller...")

    else:

        print("You may think bigger...")

    count += 1

---------------執行結果---------------

# 故意猜超過三次，看看結果

guess age:1

You may think bigger...

guess age:1

You may think bigger...

guess age:1

You may think bigger...

Process finished with exit code 0

# 先試試在三次內打對密碼，看看結果

guess age:3

You may think bigger...

guess age:36

You may think smaller...

guess age:35

Bingo, You got it!!!

Process finished with exit code 0

hmm...上面代碼成功達成條件了，接下來我們要來想想，怎麼優化這個代碼？

上面代碼是不是可以把 if count >= 3: 放進 while 裡，修改一下代碼

#!/usr/bin/env python3

# -*- coding:utf-8 -*-

age_of_ironman = 35

count = 0

while count <= 3:

    guess_age = int(input("guess age:"))

    if guess_age == age_of_ironman:

        print("Bingo, You got it!!!")

        break

    elif guess_age > age_of_ironman:

        print("You may think smaller...")

    else:

        print("You may think bigger...")

    count += 1

---------------執行結果---------------

# 故意猜超過三次，看看結果

guess age:1

You may think bigger...

guess age:69

You may think smaller...

guess age:34

You may think bigger...

Process finished with exit code 0

# 先試試在三次內打對密碼，看看結果

guess age:32

You may think bigger...

guess age:35

Bingo, You got it!!!

Process finished with exit code 0

while count < 3 就會變成有條件的，當count 小於 3就執行，如果大於3，就不執行。

但還是有稍微美中不足的地方，就是輸入超過三次，並沒有打印出任何訊息，會讓人感覺有點莫名其妙，

所以再修改一下代碼

#!/usr/bin/env python3

# -*- coding:utf-8 -*-

age_of_ironman = 35

count = 0

while count <= 3:

    guess_age = int(input("guess age:"))

    if guess_age == age_of_ironman:

        print("Bingo, You got it!!!")

        break

    elif guess_age > age_of_ironman:

        print("You may think smaller...")

    else:

        print("You may think bigger...")

    count += 1

print("You have tried too many, exit")

---------------執行結果---------------

# 故意猜超過三次，看看結果

guess age:3

You may think bigger...

guess age:3

You may think bigger...

guess age:3

You may think bigger...

You have tried too many, exit

Process finished with exit code 0

# 先試試在三次內打對密碼，看看結果

guess age:4

You may think bigger...

guess age:35

Bingo, You got it!!!

You have tried too many, exit

Process finished with exit code 0

咦~怎麼打對密碼也顯示 You have tried too many, exit，看來還做得不夠好，再修改一下代碼

#!/usr/bin/env python3

# -*- coding:utf-8 -*-

age_of_ironman = 35

count = 0

while count <= 3:

    guess_age = int(input("guess age:"))

    if guess_age == age_of_ironman:

        print("Bingo, You got it!!!")

        break

    elif guess_age > age_of_ironman:

        print("You may think smaller...")

    else:

        print("You may think bigger...")

    count += 1

if count == 3:

    print("You have tried too many, exit")

---------------執行結果---------------

# 故意猜超過三次，看看結果

guess age:1

You may think bigger...

guess age:2

You may think bigger...

guess age:3

You may think bigger...

You have tried too many, exit

Process finished with exit code 0

# 先試試在三次內打對密碼，看看結果

guess age:15

You may think bigger...

guess age:35

Bingo, You got it!!!

Process finished with exit code 0

呼，這次終於都對了…

可是我們還有另一種更牛逼的寫法，是 Python 特有的寫法

就讓我們最後一次修改代碼，讓它看起來更牛逼點!!!

#!/usr/bin/env python3

# -*- coding:utf-8 -*-

age_of_ironman = 35

count = 0

while count <= 3:

    guess_age = int(input("guess age:"))

    if guess_age == age_of_ironman:

        print("Bingo, You got it!!!")

        break

    elif guess_age > age_of_ironman:

        print("You may think smaller...")

    else:

        print("You may think bigger...")

    count += 1

else:

    print("You have tried too many, exit")

---------------執行結果---------------

# 故意猜超過三次，看看結果

guess age:4

You may think bigger...

guess age:5

You may think bigger...

guess age:6

You may think bigger...

You have tried too many, exit

Process finished with exit code 0

# 先試試在三次內打對密碼，看看結果

guess age:7

You may think bigger...

guess age:67

You may think smaller...

guess age:35

Bingo, You got it!!!

Process finished with exit code 0

終於完成了，但這個是怎麼判斷的呢？請看下圖