如何在我的程序中创建循环以使其在 python 中的每个用户选项结束时运行

Question

这是我的代码：-

f= open("Passes.py", "a+")
m=open("money.py","a+")
passes= {}
init={}
initial=0
import time
print "Welcome to the virtual banking system"
user=raw_input("Would you like to create a new account? 'Y/N'").lower()
if user== "y":
  new_user= raw_input("Create a username:")
  new_pass= raw_input("Create a password:")
  p= passes[new_user]= new_user + ":" + new_pass
  f.write("n"+p)
  ask=raw_input("Would you like to sign into your account? 'Y/N'").lower()
  if ask=="y":
    user_in=raw_input("Enter your username:")
    if user_in==new_user:
      pass_in=raw_input("Enter your password:")
      if pass_in==new_pass:
        print "Welcome to your account" + " " + new_user
        **useropt=raw_input("Would you like to view your balance- enter 1, deposit money- enter 2, withdraw money- enter 3 or exit- enter 4:")**
        if useropt=="1":
          print "Your balance is:", initial
          m.write(str(initial)+"n")
        if useropt=="2":
          amountdep= int(raw_input("How much money would you like to deposit?:"))
          initial+=amountdep
          print "Thanks. Your new balance is:", initial
          m.write(str(initial)+"n")
        if useropt=="3":
          amountwith=int(raw_input("How much would you like to withdraw?:"))
          initial-=amountwith
          print "Your balance is:", initial
          m.write(str(initial)+"n")
      else:
        print "Password not valid"
    else:
      print "Username does not exist"
  else:
    print "Thanks for using the virtual bank."
else:
  user2=raw_input("Do you have an existing account? 'Y/N'").lower()
  if user2=="y":
    existing_user=raw_input("Enter your username:")
    exisitng_pass=raw_input("Enter your password:")
    for passwords in f:
      if passwords==existing_user+":"+exisitng_pass:
        print "Welcome to your account" + " " + existing_user
        with open("money.py", "r") as m:
          info= int(m.readline().strip())
          useropt2=raw_input("Would you like to view your balance- enter 1, deposit money- enter 2, withdraw money- enter 3 or exit- enter 4:")
          if useropt2=="1":
            print "Your balance is:", info
          if useropt2=="2":
            amountdep= int(raw_input("How much money would you like to deposit?:"))
            a=info+int(amountdep)
            print "Your new balance is:", a
            with open("money.py", "w") as m:
                m.write(str(a))
          if useropt2=="3":
            amountwith=int(raw_input("How much would you like to withdraw?:"))
            t=info-int(amountwith)
            print "Your balance is:", t
            with open("money.py", "w") as m:
              m.write(str(t))

我想知道如何创建一个循环来询问用户是否要选择另一个操作，例如每次操作完成后的 useropt 变量。例如，在每个if语句的末尾，用户选择执行某个操作，我想知道如何再次询问用户是否要执行另一个操作。谢谢。

Answer 1

import time之后，你可以做：

running = True
while running:
    print "Welcome to the virtual banking system"
    #the rest of your code, indented by one.
    continue = raw_input("Would you like to do another operation? 'Y/N'").lower()
    running = continue == "y"

这将为用户提供在每次操作后退出的选项，否则重新启动。

Answer 2

你的代码应该以其他方式结构化，使用 while 循环和一个函数来处理输入。

一般示例：

# this code should go after creating a new account/entering an existing one
while True:
    Ans = raw_input("what would you like to do? 1... 2... , -1 to exit")
    int code = ProcessAns(int(Ans))
    if code == -1:
        print "bye!"
        break

# and here the function that will be called every time
def ProcessAns(ans):
    if ans == 1: 
        # do stuff
    elif ans == 2: 
        # do other stuff
    # include a way to get out
    elif ans == -1:
        return -1
    return 1