你將如何創建一個在Python中重試的選項？

Question

我對如何讓用戶重試在Python中輸入內容有點困惑。我創建了一個示例代碼。我希望如此，如果用戶鍵入1或2以外的無效答案，則允許他們再次嘗試。

import sys 

def start(): 
    print "Hello whats your name?" 
    username = raw_input("> ") 
    print "Okay, welcome to the game %s" % username 
    print "Do you want to hear the background of the game?" 
    print "1. Yes" 
    print "2. No" 

    background = raw_input("> ") 

    if background == "1": 
      print "Background goes here." 

    elif background == "2": 
     print "Background skipped" 
start() 

我該如何將再次嘗試選項納入此示例？謝謝！

Answer 1

使用while循環：

def start(): 
    print "Hello whats your name?" 
    username = raw_input("> ") 
    print "Okay, welcome to the game %s" % username 
    print "Do you want to hear the background of the game?" 
    print "1. Yes" 
    print "2. No" 
    while True:       # Repeat the following block of code infinitely 
     background = raw_input("> ") 

     if background == "1": 
      print "Background goes here." 
      break       # Break out of loop if we get valid input 
     elif background == "2": 
      print "Background skipped" 
      break       # Break out of loop if we get valid input 
     else: 
      print "Invalid input. Please enter either '1' or '2'" # From here, program jumps back to the beginning of the loop 

start()