[Tutor] Question about lists

Dave Angel d at davea.name
Fri Sep 21 15:53:30 CEST 2012

On 09/21/2012 09:31 AM, Leo Degon wrote:
> I'm trying to create a class where the main focus is creating a list whose
> elements are lists and the elements of those lists are collection of zeros
> and ones. I am trying to create functions to rotate the list ninety
> degrees, to reflect it. Having a few problems with the rotation.
> get TypeError: 'list' object is not callable

Where is the rest of the error message?  And don't forget to mention
which Python version you're using.

> def pset(n):
>     for i in n:
>         print(i)
> class board():

One Python convention which would have helped here is to use capital for
the class name, Board

Another one is to put __init__ first, since that tells us what instance
attributes you'll be using, and how they're initialized.

>     def make(self,size):
>         b=[]
>         for i in range(size[0]):
>             b.append([])
>             for j in range(size[1]):
>                 b[i].append(0)
>         return b
>     def rotate(self,board,size):

You've now defined a new local called board, which shadows the class
name board.  Is there a reason you didn't use self.board ?  As it's
presently coded, this method doesn't seem to use any instance attributes.

>         size[0],size[1]=size[1],size[0]
>         new=board(size)
>         lists=[]
>         for j in range(size[1]):
>             lists.append([])
>             for i in range(size[0]).__reversed__():
>                 lists[j].append(board[i][j])
>         for i in range(size[1]):
>             for j in range(size[0]):
>                 new.board[i,j]=lists[i,j]
>         return(new.board)
>     def __init__(self,size):
>         self.size=size
>         self.board=self.make(size)
> y=[7,7]
> x=board(y)
> pset(x.board)
> x.board[0][0]=1
> print()
> pset(x.board)
> print()
> x.board=x.rotate(x.board,x.size)
> pset(x.board)
> print()



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