Python ATM Else 和 Elif 错误

Question

我最近在 Python 3.3.3 中遇到了 Else 和 Elif 语句的一些问题。

这是我的代码：

# ATM was programmed by Jamie Mathieson

# introduction

sleep (1)

print ("-----------------------------------------------")
print ("\n                  ATM                ")
print ("\n-----------------------------------------------")

sleep (3)

print ("\nWelcome to ATM. ATM is a mathematical system that handles data.")

sleep (5)

print ("\n Your ATM card has is being inserted. Please wait...")

sleep (3)

print ("Your ATM card has been inserted.")

sleep (5)

print ("Type 'options' to view available commands.")

# variables

balance = print("Balance  £", money)

money = 200

options = ("Options: 1) Withdraw <amount> 2) Deposit <amount> 3) Balance 4) Exit")

# statements

option=int(input("Please enter an option: "))

if Option==1:
    print("Balance  £", money)

if Option==2:
    print("Balance  £", money)
    Withdraw=float(input("Please enter the amount of money you would like to withdraw: £ "))
    if Withdraw>0:
        newbalance=(money-Withdraw)
        print("New Balance: £",remainingbalance)
        elif: Withdraw>money
            print("No Balance Remaining")
        else:
            print("Withdraw canceled.")

if Option==3:
    print("Balance  £", money)
    Deposit=float(input("Please enter the amount of money you would like to deposit: £ "))
    if Deposit>0:
        newbalance=(money+Deposit)
            print("New Balance: £",newbalance)
    else:
            print("Deposit canceled.")

if Option==4:
    print("ATM is ejecting your card. Please wait...")
    sleep(5)
    exit()

我得到的错误是“无效的语法”，它突出显示了 Else 和 Elif 语句。我做错了什么？

Answer 1

您必须将 : 放在最后，并更正标识。

if Option==2:
    print("Balance  £", money)
    Withdraw=float(input("Please enter the amount of money you would like to withdraw: £ "))
    if Withdraw>0:
       newbalance=(money-Withdraw)
       print("New Balance: £",remainingbalance)
    elif Withdraw>money:
        print("No Balance Remaining")
    else:
        print("Withdraw canceled.")

Answer 2

代码有几个问题。正如@Daniel 指出的那样，您的缩进必须更正。此外，elif 块的条件放在冒号之后。

除此之外，您将用户的响应分配给名为option 的变量，然后在Option 上写入条件。这是两个不同的东西。

最后balance = print("Balance £", money) 会抛出一个错误。看起来您正在尝试将balance 定义为一个函数，该函数将打印“Balance £”，后跟余额。如果是这样，你可以这样做：

balance = lambda x: print("Balance  £{}".format(x))

编辑：要回答您的问题：sleep，请使用

from time import sleep

Answer 3

while True:

       # Reading id from user
       id = int(input("\nEnter account pin: "))
 
       # Loop till id is valid
       while id < 1000 or id > 9999:
           id = int(input("\nInvalid Id.. Re-enter: "))
 
       # Iterating over account session
       while True:
 
           # Printing menu
           print("\n1 - View Balance \t 2 - Withdraw \t 3 - Deposit \t 4 - Exit ")
 
           # Reading selection
           selection = int(input("\nEnter your selection: "))
 
           # Getting account object
           for acc in accounts:
               # Comparing account id
               if acc.getId() == id:
                   accountObj = acc
                   break
 
           # View Balance
           if selection == 1:
               # Printing balance
               print(accountObj.getBalance())
 
           # Withdraw
           elif selection == 2:
               # Reading amount
               amt = float(input("\nEnter amount to withdraw: "))
               ver_withdraw = input("Is this the correct amount, Yes or No ? " + str(amt) + " ")
 
               if ver_withdraw == "Yes":
                   print("Verify withdraw")
               else:
                   break
 
               if amt < accountObj.getBalance():
                  # Calling withdraw method
                  accountObj.withdraw(amt)
                  # Printing updated balance
                  print("\nUpdated Balance: " + str(accountObj.getBalance()) + " n")
               else:
                    print("\nYou're balance is less than withdrawl amount: " + str(accountObj.getBalance()) + " n")
                    print("\nPlease make a deposit.");
 
           # Deposit
           elif selection == 3:
               # Reading amount
               amt = float(input("\nEnter amount to deposit: "))
               ver_deposit = input("Is this the correct amount, Yes, or No ? " + str(amt) + " ")
 
               if ver_deposit == "Yes":
                  # Calling deposit method
                  accountObj.deposit(amt);
                  # Printing updated balance
                  print("\nUpdated Balance: " + str(accountObj.getBalance()) + " n")
               else:
                   break
 
           elif selection == 4:
               print("nTransaction is now complete.")
               print("Transaction number: ", random.randint(10000, 1000000))
               print("Current Interest Rate: ", accountObj.annualInterestRate)
               print("Monthly Interest Rate: ", accountObj.annualInterestRate / 12)
               print("Thanks for choosing us as your bank")
               exit()
 
           # Any other choice
           else:
               print("That's an invalid choice.")
 
# Main function
main()