python类实例化另一个类

Question

I am having trouble figuring out how to make a menu class which will instantiate a game class in python 2.7.6 I have searched other questions related to this, but still I cannot figure out how to pass parameters from one class to another. This is also my first time asking a question on stack overflow, so I am sorry if I incorrectly past my code in here.

class Lottery:
    def __init__(self, digits, betType, betAmt):
        self.digits = digits
        self.betType = betType
        self.betAmt = betAmt

    def play(self):
        print "<>" * 40
        print "Use 'mp' to play the same 'machine pick' each time"
        print "Use 'ap' to play a new 'machine pick' number each time"
        print "<>" * 40
        guess = raw_input("Choose a lottery number and see how long it takes until you win! >>")
        if guess.upper() == 'MP': #added machine pick option
            if digits == '3': #attempt support for 4 and 5 digit numbers
                choice = str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9))
            elif digits == '4':
                choice = str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9))
            elif digits == '5':
                choice = str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9))
            else:
                pass
        elif guess.upper() == 'AP': #placeholder for autopick in main loop
            pass
        else:
            choice = guess
        tries = 0
        while True:
            if guess.upper() == 'AP': #added machine pick option
                if digits == '3': #attempt support for 4 and 5 digit numbers
                    choice = str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9))
                elif digits == '4':
                    choice = str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9))
                elif digits == '5':
                    choice = str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9))
            if digits == '3': #attempt support for 4 and 5 digit numbers
                winning = str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9))
            elif digits == '4':
                winning = str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9))
            elif digits == '5':
                winning = str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9)) + str(randint(0,9))
            print winning, choice
            tries += 1
            if digits == '3':
                time.sleep(0.02)
            elif digits == '4':
                time.sleep(0.002)
            else:
                time.sleep(0.0005)
            if winning == choice:
                print "-----" * 10
                print "winner after " + str(tries) + " tries!"
                print "It took you " + str(tries/2) + " days to win!"
                print "your tickets cost $" + str(tries) + ".00"
                print "Your payout was $500"
                print "Your Net Revenue was $" + str(500 - tries) + ".00"
                print "-----" * 10
                break

and

class Menu:
    def __init__(self):
        #self.game = Lottery(digits, betType, betAmt)
        self.start()
    def start(self):
        print "Welcome to the Lottery!"
        self.digits = raw_input("Would you like to play '3' digit, '4' digit, or '5' digit? >> ")
        self.betType = raw_input("Straight, or Boxed bet type? >> ")
        self.betAmt = raw_input("$0.50, or $1.00? >> ")
        self.game = Lottery(self.digits, self.betType, self.betAmt)
        self.game.play()
        raw_input("Enter to play again")

Any help would be appreciated, I am new to Python and also Stack Overflow. Thanks :)

Traceback (most recent call last):
  File "ILR2.py", line 81, in <module>
    Menu1 = Menu()
  File "ILR2.py", line 71, in __init__
    self.start()
  File "ILR2.py", line 78, in start
    self.game.play()
  File "ILR2.py", line 38, in play
    if digits == '3': #attempt support for 4 and 5 digit numbers
NameError: global name 'digits' is not defined

This is the error I am getting when trying to run the program. Does this help? Sorry I forgot to post the first time

Answer 1

The problem is not with how you're instantiating the lottery class. That part is fine. Rather, it looks your play method in your Lottery class is buggy.

We can see this from looking at your exception:

File "ILR2.py", line 38, in play
    if digits == '3': #attempt support for 4 and 5 digit numbers
NameError: global name 'digits' is not defined

Based on context, it looks like you're trying to access the digits attribute. In order to do that, you need to use self :

if self.digits == '3':
    pass

Answer 2

I think in this situation it might not make sense to have a separate class for your menu. After all, you are storing the same information about your game in the Menu class and in the Lottery class.

You could simplify it quite a bit by adding the menu as a method within your Lottery class. Then you would not need to pass around the variables, since they are provided by the user's input anyways:

class Lottery:    
    def __init__(self):
        self.showMenu()
        self.play()

    def showMenu(self):
        # this is the code from your Menu class
        print "Welcome to the Lottery!"
        self.digits = raw_input("Would you like to play '3' digit, '4' digit, or '5' digit? >> ")
        self.betType = raw_input("Straight, or Boxed bet type? >> ")
        self.betAmt = raw_input("$0.50, or $1.00? >> ")

    def play(self):
        # gameplay code as before

Answer 3

I am NOT sure, as I can't see the code for the play() function, but it looks like you should use self.digits , not digits there. Just a guess thought.