BEGINNER: Python Value error: invalid literal for int()

Question

Im making a simple blackjack program in python, but im getting a "ValueError: invalid literal for int() with base 10: ..." In order to get the total value of the player hands, after creating the card object, i try to get the rank of the card: rank1 = Card.Card.getRank(card1)

heres the classs method:

 def getRank(self):
      if self.__rank == ('J'):
          self.__rank = 10
          return self.__rank
      elif self.__rank == ('Q'):
          self.__rank = 10
          return self.__rank
      elif self.__rank ==  ('K'):
          self.__rank = 10
          return self.__rank
      elif self.__rank == ('A'):
          self.__rank = 11
          return self.__rank
      else:
          self.__rank = self.__rank
          return int(self.__rank)`

the only time it returns the ValueError: invalid literal for int() with base 10 is if the rank is a 'Q' or 'K', it returns 10 for the 'J' and 11 for 'A'. I'm not getting why it returns an error for the 'Q' or 'K' since the code is the same for 'J' and 'A'... any help would be appreciated... if it helps, before that i had

heres the whole class

#Card class

#Class card holds ranks and suits of deck
#

TEN = 10
FOUR = 4

class Card():
     #Create rank list
     RANK= ["A", "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K"]*FOUR


     #Create list with rank names
     rankNames=[None, 'Ace', 'Two', 'Three', 'Four', 'Five', 'Six', 
                'Seven', 'Eight', 'Nine', 'Ten', 'Jack', 'Queen', 'King']


     #Create suit list
     suitNames = ['CLUBS','DIAMONDS', 'HEARTS', 'SPADES']


     #Takes in rank, suit to create a deck of cards
     def __init__(self, rank, suit):
          self.__rank = rank
          self.__suit = suit


     #Returns the rank of card
     def getRank(self):
          if self.__rank == ('J'):
              print (repr(self.__rank))
              self.__rank = 10
              return self.__rank
          elif self.__rank == ('Q'):
              self.__rank = 10
              print (repr(self.__rank))
              return self.__rank
          elif self.__rank ==  ('K'):
              print (repr(self.__rank))
              self.__rank = 10
              return self.__rank
          elif self.__rank == ('A'):
              print (repr(self.__rank))
              self.__rank = 11
              return self.__rank
          else:
              self.rank = self.__rank
              print (repr(self.__rank))
              return int(self.__rank)   


     #Returns suit of card
     def getSuit(self):
          return self.__suit


     #Returns number of points the card is worth
     def BJVaue(self):
          if self.rank < 10:
               return self.rank
          else:
               return TEN


     def __str__(self):
          return "%s of %s" % ([self.__rank], [self.__suit])

Heres where i create the card objects

#Create a player hand                
player = []    
#Draw two cards for player add append
player.append(drawCard())
player.append(drawCard())

#Display players cards
print ("You currently have:\n" , player)

#Get the rank of the card
card1 = player[0]
card2 = player[1]

#Update players card status
print (card1)
print (card2)

#Get the total of the hand
rank1 = Card.Card.getRank(card1)
rank2 = Card.Card.getRank(card2)

#Get the ranks of players cards
playerRank = [rank1 , rank2]

#Get total of players hand
totalPlayer = getTotal(playerRank)

#Display players total
print ("Your current total is: ", totalPlayer)

the getTotal function

def getTotal(rank):
    #Create and set accumulator to 0
    total = 0

    #for each value in the rank
    for value in rank:
        #add to total
        total += value

    #Return total
    return total

hope this helps

it doesn't even get that far before the error shows...it is telling the error is in the same line as the elif statement — Confused
– Confused, Commented Dec 13, 2010 at 0:10
You need to post more code. How does self.__rank get defined? — Falmarri
– Falmarri, Commented Dec 13, 2010 at 0:10
You should really try simpler examples first. You have clear, fundamental deficiencies in your understanding of programming in general. Setting an instance variable, and then returning that same variable right after that is generally (not always), a flaw in your design. — Falmarri
– Falmarri, Commented Dec 13, 2010 at 0:15

Laurence Gonsalves · Accepted Answer · 2010-12-13 00:10:40Z

3

This line isn't right:

  if self.__rank == ('J' or 'Q' or 'K'):

('J' or 'Q' or 'K') evaluates to 'J', so this line just checks whether self.__rank == 'J'.

You actually want:

  if self.__rank in ('J', 'Q', 'K'):

I think your first code example should work. Are you sure that you're actually running the new code? If you try to import the same module into a running Python instance it won't pick up the changes. Also, if you redefine a class, existing instances will still have the old method implementations.

answered Dec 13, 2010 at 0:10

Laurence Gonsalves

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4 Comments

John La Rooy Over a year ago

or more compactly: if self.__rank in 'JQK':

Laurence Gonsalves Over a year ago

@gnibbler True, though I kind of feel that that's on the verge of obfuscation. 'JQK' contains more than 'J', 'Q' and 'K'. It also contains 'JQ', 'QK', 'JQK' and '', none of which is probably desirable.

John La Rooy Over a year ago

using conditionals here at all is obfuscating. In my opinion a dict would be cleaner

Laurence Gonsalves Over a year ago

@gnibbler I agree that a dict is probably the right solution. The setting of self.__rank as a result of retrieving it also seems odd, but I wasn't trying to rewrite all of his code, just make it do what he intended for it to do.

Hugh Bothwell · Accepted Answer · 2010-12-13 17:36:42Z

You've got fairly stinky code here - bad indentation, unnecessary brackets (are those strings or tuples?), nasty mix of functional and OO, static calls to non-static methods, etc.

The initial problem, "ValueError: invalid literal for int() with base 10: ..." means you are passing int() a value which it doesn't know how to translate into an integer. The question, then, is: what is that value, and where is it coming from?

Try substituting

    VALUE = {
        '2':2, '3':3, '4':4, '5':5, '6':6, '7':7, '8':8, '9':9, '10':10,
        'J':10, 'Q':10, 'K':10, 'A':11
    }
    def getValue(self):
        try:
            return Card.VALUE[self.__rank]
        except KeyError:
            print "%s is not a valid rank" % (self.__rank)

and see what you get. My guess would be that drawCard is generating rank values that Card.getValue doesn't know what to do with.

Other problems with your code:

TEN = 10
FOUR = 4

The whole point of using defined values is to provide semantic meaning and allow a single point of change; yet FOUR is no more contextually meaningful than 4, and I see no case in which changing the value of FOUR or TEN would make sense (indeed, if FOUR were ever to equal 3, it would be actively unhelpful in understanding your code). Try renaming them FACECARD_VALUE and NUMBER_OF_SUITS.

You are using "rank" to mean multiple different things: the character denoting a card and the value of a card to your hand. This will also increase confusion; try using face for one and value for the other!

You seem to be using drawCard() as a stand-alone function; how are you keeping track of what cards have already been dealt? Does it ever make sense to have, for example, two Ace of Spades cards dealt? I would suggest creating a Deck object which initializes 52 canonical cards, shuffles them, and then deck.getCard() returns a card from the list instead of creating it randomly.

See what you think of the following:

import random

class Deck():
    def __init__(self):
        self.cards = [Card(f,s) for f in Card.FACE for s in Card.SUIT]
        self.shuffle()

    def shuffle(self):
        random.shuffle(self.cards)

    def getCard(self):
        return self.cards.pop()

class Card():
    # Class static data
    FACE = ('A',   '2',   '3',     '4',    '5',    '6',   '7',     '8',     '9',    '10',  'J',    'Q',     'K')
    NAME = ('Ace', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine', 'Ten', 'Jack', 'Queen', 'King')
    RANK = (11,    2,     3,       4,      5,      6,     7,       8,       9,      10,    10,     10,      10)
    SUIT = ('Clubs','Diamonds', 'Hearts', 'Spades')

    def __init__(self, face, suit):
        ind = Card.FACE.index(face)
        self.__face = Card.FACE[ind]   # the long way around, but keeps it consistent
        self.__name = Card.NAME[ind]
        self.__rank = Card.RANK[ind]

        ind = Card.SUIT.index(suit)
        self.__suit = Card.SUIT[ind]

    def getFace(self):
        return self.__face

    def getName(self):
        return self.__name

    def getRank(self):
        return self.__rank

    def getSuit(self):
        return self.__suit

    def __str__(self):
        return "%s of %s" % (self.__name, self.__suit)

    def __repr__(self):
        return "%s%s" % (self.__face, self.__suit[:1])

class Player():
    def __init__(self):
        self.cards = []

    def drawCard(self, deck):
        self.cards.append(deck.getCard())

    def drawCards(self, deck, num=2):
        for i in range(num):
            self.drawCard(deck)

    def getRank(self):
        return sum( c.getRank() for c in self.cards )

    def __str__(self):
        cards = ', '.join(str(c) for c in self.cards)
        return  "%s: %d" % (cards, self.getRank())

    def __repr__(self):
        return ' '.join([repr(c) for c in self.cards])

class Game():
    def __init__(self):
        self.deck = Deck()
        self.player1 = Player()
        self.player2 = Player()

    def test(self):
        self.player1.drawCards(self.deck, 2)
        print "Player 1:", self.player1

        self.player2.drawCards(self.deck, 2)
        print "Player 2:", self.player2

def main():
    g = Game()
    g.test()

if __name__=="__main__":
    main()

Falmarri · Accepted Answer · 2010-12-13 00:18:40Z

0

rank1 = Card.Card.getRank(card1)

This looks like you're trying to call the getRank as a static method. getRank is expecting an instance of itself as the first parameter. This usually means you have a Card object, but the way you call it above, you don't have an object to pass it. ~~I'ms urprised it even lets you call it like that. That should give you an incorrect number of arguments error.~~

Post more code, but it seems like you have serious fundamental problems with your design.

Update:

What's this?

RANK= ["A", "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K"]*FOUR

Why do you need a list of 4 duplicates of your ranks?

edited Dec 13, 2010 at 0:18

answered Dec 13, 2010 at 0:13

Falmarri

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2 Comments

Ignacio Vazquez-Abrams Over a year ago

Unless card1 is the Card object. Which still doesn't make it any less pathological mind...

Confused Over a year ago

idk i didnt write the class my partner did...i think because theres four suits so that means theres four of each card in a deck... it doesnt make sense to me either because im just taking a random rank anyways so it doesnt make a difference

John La Rooy · Accepted Answer · 2010-12-13 01:53:12Z

0

Here is another approach to make a deck of cards

from itertools import product

card_values = (
    ("1", "1", 1),
    ("2", "2", 2),
    ("3", "3", 3),
    ("4", "4", 4),
    ("5", "5", 5),
    ("6", "6", 6),
    ("7", "7", 7),
    ("8", "8", 8),
    ("9", "9", 9),
    ("10" ,"10", 10),
    ("Jack", "J", 10),
    ("Queen", "Q", 10),
    ("King", "K", 10),
    ("Ace", "A", 11))

card_suits = ("Spades", "Clubs", "Hearts", "Diamonds")

class Card(object):
    def __init__(self, name, short_name, rank, suit):
        self.name = name
        self.short_name = short_name
        self.rank = rank
        self.suit = suit  

cards = []
for (name, short_name, rank), suit in product(card_values, card_suits):
    cards.append(Card(name, short_name, rank, suit))

edited Dec 13, 2010 at 1:53

answered Dec 13, 2010 at 0:38

John La Rooy

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Comments

martineau · Accepted Answer · 2010-12-13 05:44:57Z

0

You could reduce the amount and complexity of your code by using a Python dictionary. If you did this, your getRank() function could look something like the following:

class Card(object):
    RANK = {"A":1, "2":2,  "3": 3, "4":4,  "5": 5, "6": 6, "7":7,
            "8":8, "9":9, "10":10, "J":10, "Q":10, "K":10}

    def __init__(self, draw): # just for example
        self.__rank = draw

    def getRank(self):
        self.__rank = Card.RANK[self.__rank]
        return self.__rank
    #  ...

print Card('A').getRank()
# 1
print Card('4').getRank()
# 4
print Card('J').getRank()
# 10
print Card('K').getRank()
# 10

edited Dec 13, 2010 at 5:44

answered Dec 13, 2010 at 0:35

martineau

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3 Comments

Confused Over a year ago

we never used one before...i'll look into it and see what i can do with it...thanks

aaronasterling Over a year ago

@Confused You are indeed confused if you think you've never used a dictionary before. Most of Python's object model and global namespaces are build on dictionaries.

martineau Over a year ago

@Confused: Dictionaries in Python are a lot like lists except the index can something other than an index, like a string -- which is what is shown in the code above.

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