前の行を実行していますか？

Question

飛行機に十分な座席がない場合、飛行機を予約することはできませんが、前回のコード行（8行目）に戻りたいと思います。

while True: 
    if b == maxpass and booking == "b" or booking == "book": 
     print ("Sorry but the flight you want is currently fully booked. Sorry for Inconviniance") 

     print ("Welcome to Flight Booking Program") 
     print ("Please enter the flight number you want to book/cancel with? (Case Sensitve)") 
     flight = input() 

繰り返しています。ここで

は、コードの残りの部分である：

# b means bookings, fn means Flight Number 
b = 0 
maxpass = 68 
minpass = 0 
fn = "FNO123" 
amount = 0 
seatsremain = 68 - b 

print ("Welcome to Flight Booking Program") 

print ("Please enter the flight number you want to book/cancel with? (Case Sensitve)") 
flight = input() 

while flight != "X": 
    seatsremain = 68 - b 

    while True: 
     if flight == fn: 
      print ("There are currently", seatsremain, "seats remaining") 
      break 
     else: 
      print ("ERROR") 
      print ("Not a valid flight number! Remember input is CASE SENSITIVE") 
      print ("Welcome to Flight Booking Program") 
      print ("Please enter the flight number you want to book/cancel with? (Case Sensitve)") 
      flight = input() 

    print ("Would you like to book or cancel your flight?") 
    booking = input().lower()   

    while True: 
     if b == maxpass and booking == "b" or booking == "book": 
      print ("Sorry but the flight you want is currently fully booked. Sorry for Inconviniance") 

      print ("Welcome to Flight Booking Program") 
      print ("Please enter the flight number you want to book/cancel with? (Case Sensitve)") 
      flight = input() 


     else: 
      break 

    if booking == "c" or booking == "b" or booking == "book" or booking == "cancel": 
     if booking == "b" or booking == "book": 
      print ("How many seats are you booking?") 
      while True: 
       try: 
        amount = int(input()) 
        if amount <1 or amount >seatsremain: 
         print ("ERROR") 
         print ("You must book at least 1 seat and not exceed the maximum amount of seats avaliable") 
         print ("There are currently", seatsremain, "seats remaining") 
         print ("How many seats are you booking?") 
        else: 
         b = b + amount 
         print ("Your flight has been Booked!") 
         print ("Welcome to Flight Booking Program") 
         print ("Please enter the flight number you want to book/cancel with? (Case Sensitve)") 
         flight = input() 
         break 
       except ValueError: 
        print ("You must enter a valid number!") 

     else: 
      if booking == "c" or booking == "cancel": 
       print ("How many seats are you canceling?") 
       while True: 
        try: 
         amount = int(input()) 
         if amount <1 or amount >b: 
          print ("ERROR") 
          print ("You must cancel at least 1 seat and not exceed the minimum amount of seats avaliable") 
          print ("There are currently", seatsremain, "seats remaining") 
          print ("How many seats are you cancelling?") 
         else: 
          b = b - amount 
          print ("Your flight has been Cancelled!") 
          print ("Welcome to Flight Booking Program") 
          print ("Please enter the flight number you want to book/cancel with? (Case Sensitve)") 
          flight = input() 
          break 
        except ValueError: 
         print ("You must enter a valid number!") 
    else: 
     print ("Error") 
     print ("Please only type book or cancel") 


print("There are", b, "people booked on flight", fn) 

Answer 1

それはあなたが求めているものを100％明確ではないのですが、私はあなたがこのような何かしたい疑う：ここ

class MyOwnError(Exception): 
    def __init__(self, message): 
     self.message = message 
    def __str__(self): 
     return repr(self.message) 

while flight != "X": 
    try: 
     seatsremain = 68 - b 


     if flight == fn: 
      print ("There are currently", seatsremain, "seats remaining") 
     else: 
      raise MyOwnError("Not a valid flight number!") 

     # etc... 
        if amount <1 or amount >b: 
         print ("ERROR") 
         print ("You must cancel at least 1 seat and not exceed the minimum amount of seats avaliable") 
         print ("There are currently", seatsremain, "seats remaining") 
         print ("How many seats are you cancelling?") 
        else: 
         b = b - amount 
         raise MyOwnError("Your flight has been Cancelled!") 
     # etc... 

    except MyOwnError as e: 
     print (e.message) 
     print ("Welcome to Flight Booking Program") 
     print ("Please enter the flight number you want to book/cancel with? (Case Sensitve)") 
     flight = input() 

例外力ジャンプすべてのループから抜け出し、入力を再度促すことができます。ネストされたtry/exceptステートメントを使用することによって、このアイデアを展開してシートキャンセルループにも対処できます。