Python: Object does not support indexing

Jonathan Spirit picture Jonathan Spirit · Mar 17, 2014 · Viewed 84.9k times · Source

Yes, this question has been asked before. No, none of the answers I read could fix the problem I have.

I'm trying to create a little Bounce game. I've created the bricks like this:

def __init__(self,canvas):
    self.canvas = canvas
    self.brick1 = canvas.create_rectangle(0,0,50,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.brick2 = canvas.create_rectangle(50,0,100,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.brick3 = canvas.create_rectangle(100,0,150,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.brick4 = canvas.create_rectangle(150,0,200,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.brick5 = canvas.create_rectangle(200,0,250,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.brick6 = canvas.create_rectangle(250,0,300,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.brick7 = canvas.create_rectangle(300,0,350,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.brick8 = canvas.create_rectangle(350,0,400,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.brick9 = canvas.create_rectangle(400,0,450,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.brick10 = canvas.create_rectangle(450,0,500,20,fill=random_fill_colour(),outline=random_fill_colour())
    self.bricksId = [self.brick1,self.brick2,self.brick3,self.brick4,self.brick5,self.brick6,self.brick7,self.brick8,self.brick9,self.brick10]

And I'm trying to reference the ID of bricksId[0] over here:

self.hit_brick(pos,self.bricks.bricksId[0])

Earlier, in the __init__, I define bricks as bricks, which is defined as Brick(canvas). However, the error states:

TypeError: 'Brick' object does not support indexing

In the answers to the other questions of this subject, I cannot find any that help me access bricks.bricksId[0].

Answer

bitsplit picture bitsplit · Mar 17, 2014

In order for the Brick object to be indexable, you must implement the methods:

  • __getitem__
  • __setitem__
  • __delitem__

You don't need all of them, only the ones you use.

However, this seems like a case of self.bricks being a brick instead of a list of bricks. A list of bricks is indexable; however, a brick itself is not unless you implement the methods above.

Check this for reference.


In order to be able to call self.bricks.bricksId[number] when I needed:

def __getitem__(self,index):
    return self.bricks.bricksId[index]

def __setitem__(self,index,value):
    self.bricks.bricksId[index] = value