[Tutor] Blackjack Betting

[Prasad, Ramit]

>I keep getting the error: “NameError: global
>name 'bet' is not defined.” I know I came across this error before in a
>previous thread, but I am confused on how to solve this, since I am also
>trying to juggle it with inherited methods at the same time.

Telling us this without the stack trace is pretty unhelpful. The Python exceptions include a very good stack trace (with line numbers +- 1 line) and a decent description. This error means that wherever this error was raised was a reference to the name "bet" and it had no reference to any "bet" at that point. The reasons could be that you forgot to assign a value to the name first, maybe it was a typo, in a preceding function, forgot the reference to self, etc, etc.

I took a *quick* look at the code and found this (I did not check for other problems or if this error happens in more than one place):


class BJ_Player(BJ_Hand, Bet):
    """ A Blackjack Player. """
    def is_hitting(self):
        response = games.ask_yes_no("\n" + self.name + ", do you want a hit? (Y/N): ")
        return response == "y"

    def bust(self):
        print(self.name, "busts.")
        self.lose()

    def lose(self):
        print(self.name, "loses.")
        betting = Bet()
        bet.stash -= bet.wager

    def win(self):
        print(self.name, "wins.")
        bet = Bet()
        bet.stash += bet.wager

    def push(self):
        print(self.name, "pushes.")


There are a couple things wrong with this class. First, you never define an __init__ which might be technically okay but is unlikely to be what you want for any user defined class (especially one with multiple inheritance). Since there is no __init__ defined, it will call the first parent class BJ_Hand.__init__ but not the second parent class Bet.__init__ (if it has one). 

Next for BJ_Player.lose(), bet is never defined and thus neither is bet.stash. Maybe you meant betting.stash -= betting.wager? I bet if you ran lint/pylint on this module it would have told you the error without even having to run it.


Ramit


Ramit Prasad | JPMorgan Chase Investment Bank | Currencies Technology
712 Main Street | Houston, TX 77002
work phone: 713 - 216 - 5423



-----Original Message-----
From: tutor-bounces+ramit.prasad=jpmchase.com at python.org [mailto:tutor-bounces+ramit.prasad=jpmchase.com at python.org] On Behalf Of Vincent Balmori
Sent: Thursday, June 30, 2011 1:49 PM
To: tutor at python.org
Subject: [Tutor] Blackjack Betting


I have been working on another challenge that involves improving the
Blackjack program so the players can wager an amount. If a player loses they
will be removed from the game.  I keep getting the error: “NameError: global
name 'bet' is not defined.” I know I came across this error before in a
previous thread, but I am confused on how to solve this, since I am also
trying to juggle it with inherited methods at the same time. Here is the old
and new file for the blackjack program for comparison:

http://old.nabble.com/file/p31966195/blackjack.py blackjack.py 
http://old.nabble.com/file/p31966195/blackjackbetting.py blackjackbetting.py 
-- 
View this message in context: http://old.nabble.com/Blackjack-Betting-tp31966195p31966195.html
Sent from the Python - tutor mailing list archive at Nabble.com.

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