Hi everyone. Very simple set up for the problem, strange problem.
class Deck:
def __init__(self):
self.cards = []
for suit in range(4):
for rank in range(1,14):
self.cards.append(Card(suit,rank))
def __str__(self):
for card in self.cards:
print card
__str__() should *return* a string representation of the object, not print it! Your __str__() method prints the Deck and returns None, which is the source of the error. Try
def __str__(self):
return '\n'.join(str(card) for card in self.cards)
Kent
### End of Cards.py ###
Nothing wrong, right? So I fire up the interpreter and enter these commands
Python 2.4 (#60, Nov 30 2004, 11:49:19) [MSC v.1310 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
from Cards import * a = Deck() print a
Ace of Clubs 2 of Clubs 3 of Clubs 4 of Clubs 5 of Clubs 6 of Clubs 7 of Clubs 8 of Clubs 9 of Clubs 10 of Clubs Jack of Clubs Queen of Clubs King of Clubs Ace of Diamonds 2 of Diamonds 3 of Diamonds 4 of Diamonds 5 of Diamonds 6 of Diamonds 7 of Diamonds 8 of Diamonds 9 of Diamonds 10 of Diamonds Jack of Diamonds Queen of Diamonds King of Diamonds Ace of Hearts 2 of Hearts 3 of Hearts 4 of Hearts 5 of Hearts 6 of Hearts 7 of Hearts 8 of Hearts 9 of Hearts 10 of Hearts Jack of Hearts Queen of Hearts King of Hearts Ace of Spades 2 of Spades 3 of Spades 4 of Spades 5 of Spades 6 of Spades 7 of Spades 8 of Spades 9 of Spades 10 of Spades Jack of Spades Queen of Spades King of Spades Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: __str__ returned non-string (type NoneType)
Python 2.4 (#60, Nov 30 2004, 11:49:19) [MSC v.1310 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
from Cards import * a = Deck() print a
Ace of Clubs 2 of Clubs 3 of Clubs 4 of Clubs 5 of Clubs 6 of Clubs 7 of Clubs 8 of Clubs 9 of Clubs 10 of Clubs Jack of Clubs Queen of Clubs King of Clubs Ace of Diamonds 2 of Diamonds 3 of Diamonds 4 of Diamonds 5 of Diamonds 6 of Diamonds 7 of Diamonds 8 of Diamonds 9 of Diamonds 10 of Diamonds Jack of Diamonds Queen of Diamonds King of Diamonds Ace of Hearts 2 of Hearts 3 of Hearts 4 of Hearts 5 of Hearts 6 of Hearts 7 of Hearts 8 of Hearts 9 of Hearts 10 of Hearts Jack of Hearts Queen of Hearts King of Hearts Ace of Spades 2 of Spades 3 of Spades 4 of Spades 5 of Spades 6 of Spades 7 of Spades 8 of Spades 9 of Spades 10 of Spades Jack of Spades Queen of Spades King of Spades Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: __str__ returned non-string (type NoneType)
Python 2.4 (#60, Nov 30 2004, 11:49:19) [MSC v.1310 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
from Cards import * a = Deck() print a
Ace of Clubs 2 of Clubs 3 of Clubs 4 of Clubs 5 of Clubs 6 of Clubs 7 of Clubs 8 of Clubs 9 of Clubs 10 of Clubs Jack of Clubs Queen of Clubs King of Clubs Ace of Diamonds 2 of Diamonds 3 of Diamonds 4 of Diamonds 5 of Diamonds 6 of Diamonds 7 of Diamonds 8 of Diamonds 9 of Diamonds 10 of Diamonds Jack of Diamonds Queen of Diamonds King of Diamonds Ace of Hearts 2 of Hearts 3 of Hearts 4 of Hearts 5 of Hearts 6 of Hearts 7 of Hearts 8 of Hearts 9 of Hearts 10 of Hearts Jack of Hearts Queen of Hearts King of Hearts Ace of Spades 2 of Spades 3 of Spades 4 of Spades 5 of Spades 6 of Spades 7 of Spades 8 of Spades 9 of Spades 10 of Spades Jack of Spades Queen of Spades King of Spades Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: __str__ returned non-string (type NoneType)
Python 2.4 (#60, Nov 30 2004, 11:49:19) [MSC v.1310 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
from Cards import * a = Deck() print a
Ace of Clubs 2 of Clubs 3 of Clubs 4 of Clubs 5 of Clubs 6 of Clubs 7 of Clubs 8 of Clubs 9 of Clubs 10 of Clubs Jack of Clubs Queen of Clubs King of Clubs Ace of Diamonds 2 of Diamonds 3 of Diamonds 4 of Diamonds 5 of Diamonds 6 of Diamonds 7 of Diamonds 8 of Diamonds 9 of Diamonds 10 of Diamonds Jack of Diamonds Queen of Diamonds King of Diamonds Ace of Hearts 2 of Hearts 3 of Hearts 4 of Hearts 5 of Hearts 6 of Hearts 7 of Hearts 8 of Hearts 9 of Hearts 10 of Hearts Jack of Hearts Queen of Hearts King of Hearts Ace of Spades 2 of Spades 3 of Spades 4 of Spades 5 of Spades 6 of Spades 7 of Spades 8 of Spades 9 of Spades 10 of Spades Jack of Spades Queen of Spades King of Spades Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: __str__ returned non-string (type NoneType)
a.cards
[Ace of Clubs, 2 of Clubs, 3 of Clubs, 4 of Clubs, 5 of Clubs, 6 of Clubs, 7 of
Clubs, 8 of Clubs, 9 of Clubs, 10 of Clubs, Jack of Clubs, Queen of Clubs, King
of Clubs, Ace of Diamonds, 2 of Diamonds, 3 of Diamonds, 4 of Diamonds, 5 of Dia
monds, 6 of Diamonds, 7 of Diamonds, 8 of Diamonds, 9 of Diamonds, 10 of Diamond
s, Jack of Diamonds, Queen of Diamonds, King of Diamonds, Ace of Hearts, 2 of He
arts, 3 of Hearts, 4 of Hearts, 5 of Hearts, 6 of Hearts, 7 of Hearts, 8 of Hear
ts, 9 of Hearts, 10 of Hearts, Jack of Hearts, Queen of Hearts, King of Hearts,
Ace of Spades, 2 of Spades, 3 of Spades, 4 of Spades, 5 of Spades, 6 of Spades,
7 of Spades, 8 of Spades, 9 of Spades, 10 of Spades, Jack of Spades, Queen of Sp
ades, King of Spades]
for card in a.cards:
... print card ... Ace of Clubs 2 of Clubs 3 of Clubs 4 of Clubs 5 of Clubs 6 of Clubs 7 of Clubs 8 of Clubs 9 of Clubs 10 of Clubs Jack of Clubs Queen of Clubs King of Clubs Ace of Diamonds 2 of Diamonds 3 of Diamonds 4 of Diamonds 5 of Diamonds 6 of Diamonds 7 of Diamonds 8 of Diamonds 9 of Diamonds 10 of Diamonds Jack of Diamonds Queen of Diamonds King of Diamonds Ace of Hearts 2 of Hearts 3 of Hearts 4 of Hearts 5 of Hearts 6 of Hearts 7 of Hearts 8 of Hearts 9 of Hearts 10 of Hearts Jack of Hearts Queen of Hearts King of Hearts Ace of Spades 2 of Spades 3 of Spades 4 of Spades 5 of Spades 6 of Spades 7 of Spades 8 of Spades 9 of Spades 10 of Spades Jack of Spades Queen of Spades King of Spades
len(a.cards)
52
Why am I getting a NoneType in my loop?
Any help appreciated. Jacob _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
_______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
