我如何在python中無限循環這個程序？

Question

好的，我剛剛開始學習python，不知道還有什麼地方可以提出這個問題。我寫了這個計算器，它的工作原理。

a,b=input("Enter two numbers (sperated by a comma): ") 
operator=raw_input("Do you want to add, subtract, multiply, or divide? ") 
if operator=="divide": 
    print "Your answer is", a/b 
if operator=="multiply": 
    print "Your answer is", a * b 
if operator=="add": 
    print "Your answer is", a + b 
if operator=="subtract": 
    print "Your answer is", a - b  
repeat=raw_input("Do you want to perform another calculation(yes or no)? ") 

現在，我想知道如何重新啓動這個程序，如果輸入是肯定的。我搜索了一個答案，但我無法弄清楚循環整個事情的命令。就像在while循環中一樣，你必須在條件之後提供一個命令，但是該命令是什麼？哈爾普。

Answer 1

Try this
 
You can use while True: with this the code written inside the for loop 
will execute infinitely,
To stop execution you can use Ctrl + C 
 
while True:
    a,b=input("Enter two numbers (sperated by a comma): ")
    operator=raw_input("Do you want to add, subtract, multiply, or divide? ")
    if operator=="divide":
        print "Your answer is", a/b
    if operator=="multiply":
        print "Your answer is", a * b
    if operator=="add":
        print "Your answer is", a + b
    if operator=="subtract":
        print "Your answer is", a - b 
    repeat=raw_input("Do you want to perform another calculation(yes or no)? ") 
    if repeat == "no": 
        break

Answer 2

while True: 
    a,b=input("Enter two numbers (sperated by a comma): ") 
    operator=raw_input("Do you want to add, subtract, multiply, or divide? ") 
    if operator=="divide": 
     print "Your answer is", a/b 
    if operator=="multiply": 
     print "Your answer is", a * b 
    if operator=="add": 
     print "Your answer is", a + b 
    if operator=="subtract": 
     print "Your answer is", a - b  
    repeat=raw_input("Do you want to perform another calculation(yes or no)? ") 
    if repeat == 'no': 
     break 

雖然真正的永續循環，它可以通過關鍵字突破（它打破了最近的循環（for或while））被打破。

當處理來自用戶的輸入以確定條件時，最好檢查來自用戶的輸入是以「y」（是）開始還是以「n」（否）開始，因爲用戶可能會輸入y的是他可能惹的資本，下面是實現此代碼：

while True: 
    a,b=input("Enter two numbers (sperated by a comma): ") 
    operator=raw_input("Do you want to add, subtract, multiply, or divide? ") 
    if operator=="divide": 
     print "Your answer is", a/b 
    if operator=="multiply": 
     print "Your answer is", a * b 
    if operator=="add": 
     print "Your answer is", a + b 
    if operator=="subtract": 
     print "Your answer is", a - b  
    repeat=raw_input("Do you want to perform another calculation(yes or no)? ") 
    if repeat.lower.startswith('n'): 
     break 

「重複」是一個字符串，它有一個方法（類同功能）被稱爲「低」，則此方法返回小寫字母表示，那麼你可以通過使用另一個叫做startswith的方法來檢查小寫表示（也是一個字符串）是否以字母「n」開頭。只要答案是「是」（不區分大小寫）

repeat = "yes" 
while repeat.lower().strip() == 'yes': 
    a,b=input("Enter two numbers (sperated by a comma): ") 
    operator=raw_input("Do you want to add, subtract, multiply, or divide? ") 
    if operator=="divide": 
     print "Your answer is", a/b 
    if operator=="multiply": 
     print "Your answer is", a * b 
    if operator=="add": 
     print "Your answer is", a + b 
    if operator=="subtract": 
     print "Your answer is", a - b  
    repeat=raw_input("Do you want to perform another calculation(yes or no)? ") 

這將循環：

Answer 3

把它包在while循環。最初的「重複」是保證循環至少運行一次。

順便說一句，你可以把你if考不上的字典：

import operator 
ops = {'divide': operator.div, 
     'multiply': operator.mul, 
     'add': operator.add, 
     'subtract': operator.sub} 
repeat = "yes" 
while repeat.lower().strip() == 'yes': 
    a,b=input("Enter two numbers (sperated by a comma): ") 
    operator=raw_input("Do you want to add, subtract, multiply, or divide? ").lower().strip() 
    if operator not in ops: 
     print 'Invalid operator:', operator 
     continue 
    print "Your answer is", ops[operator](a,b) 
    repeat=raw_input("Do you want to perform another calculation(yes or no)? ") 

Answer 4

試試這個：

while True:  
    a,b=input("Enter two numbers (sperated by a comma): ") 
    operator=raw_input("Do you want to add, subtract, multiply, or divide? ") 
    if operator=="divide": 
     print "Your answer is", a/b 
    if operator=="multiply": 
     print "Your answer is", a * b 
    if operator=="add": 
     print "Your answer is", a + b 
    if operator=="subtract": 
     print "Your answer is", a - b  
    repeat=raw_input("Do you want to perform another calculation(yes or no)? ") 
    if repeat == "no": 
     break