Newbie help understanding...

[mark]

Hi I am trying to get a piece of code to work based on an exercise in
a book. Any help appreciated. Can someone please explain what is going
on here.

I am trying to read from a text file a list of cards with the
following format and sort firstly by suit and then by rank

h 1
d 2
c 5
s 9
h2
d3

etc...

I get the following error;
Traceback (most recent call last):
  File "F:/###UNI###/ITC106/ass2/cardread.py", line 25, in <module>
    t.append( t[0] + 400 )
AttributeError: 'str' object has no attribute 'append'

def read_cards(filename):
    cards = []
    for card in open(filename, 'r'):
        cards.append(card.strip())
    return cards

# read the deck of cards from a file
filename = 'cards.txt'
cards = read_cards(filename)


for t in read_cards(filename):
    if t[1] == 'h':
        t.append( t[0] + 100 )
    elif t[1] == 'd':
        t.append( t[0] + 200 )
    elif t[1] == 'c':
        t.append( t[0] + 300 )
    else:
        t.append( t[0] + 400 )



print read_cards(filename)

Regards


J