Converting a bidimensional list in a bidimensional array

[Santiago Romero]

 Hi :)

 First of all, I must apologize for my poor english :)

 I'm starting with python and pygame and for testing (and learning)
purposes I wrote an small "Map Editor" for a small game project I'm
going to start next month.

 The tilemap editor is working fine, but reading Guido's Van Rossum
PYTHON TUTORIAL I found that my game map is "wasting" memory by using
about 16 bytes for each item in it, because every item in a python
list takes 16 bytes in memory. In the same tutorial, I found
references to the "array()" function of the "array" module.

 I'm trying to change my current working source code so that it works
with an array instead of using a list, but I'm not managing to do it.

 My tilemap is something like (think on 0=empty, 1=floor, 2=rock, and
so...):

[
[0 ,0, 0, 0, 0, 0, 0, 0 ,0],
[0 ,0, 0, 0, 0, 0, 0, 0 ,0],
[2 ,0, 0, 0, 0, 2, 2, 0 ,0],
(...)
[2 ,2, 0, 0, 2, 2, 2, 0 ,0],
[1 ,1, 1, 1, 1, 1, 1, 1 ,1],
]

 This is how I create the tilemap (and the clipboard, a copy of my
tilemap):

    def __init__( self, bw, bh, tiles ):
      self.width, self.height = bw, bh
      self.tilemap = []
      self.clipboard = []
      (...)
      for i in range(bh):
         self.tilemap.append([0] * bw)
         self.clipboard.append([0] * bw)


 And that's how I'm using it (the functions I'm having trouble to
convert to use the array):

   #-------------------------------------
   def CopyToClipboard( self ):
      for j in range( self.height ):
         self.clipboard[j][:] = self.tilemap[j][:]

   #-------------------------------------
   def Draw( self, clear=1 ):
      screen = pygame.display.get_surface()
      if clear: self.Clear()

      for j in range(self.GetHeight()):
         for i in range(self.GetWidth()):
            self.DrawBlock( i, j )

   #-------------------------------------
   def DrawBlock( self, x, y ):
      screen = pygame.display.get_surface()
      xd = (x * self.TileWidth()) + self.originx;
      yd = (y * self.TileHeight()) + self.originy;
      b = self.tilemap[y][x]
      self.tileset.tiles[b].Draw( screen, xd, yd )

   #-------------------------------------
   def ResizeWidth( self, new ):
      bw, bh = self.GetWidth(), self.GetHeight()

      if new > bw:
         for j in range(bh):
            for i in range(new-bw):
               self.tilemap[j].append( 0 )
               self.clipboard[j].append( 0 )
         self.SetWidth( new )

      elif new < bw:
         for j in range(bh):
            for i in range(bw-new):
               del self.tilemap[j][-1]
               del self.clipboard[j][-1]
         self.SetWidth( new )

   #-------------------------------------
   def ResizeHeight( self, new ):
      bw, bh = self.GetWidth(), self.GetHeight()

      if new > bh:
         for i in range(new-bh):
            self.tilemap.append([0] * bw)
            self.clipboard.append([0] * bw)
         self.SetHeight( new )

      elif new < bh:
         for i in range(1,bh-new):
             del self.tilemap[-1]
         self.SetHeight( new )



In fact, I'm even unable to create the array correctly:


 I've tried:

      self.tilemap = array('H', [])

      for i in range(bh):
         self.tilemap.append([0] * bw)

 and:

      for i in range(bh):

         for j in range(bw):
            self.tilemap[i].append(0)


 But I receive errors like (either defining or using the array):

 b = self.tilemap[y][x]
TypeError: 'int' object is unsubscriptable

 or:

self.tilemap.append( [0] * bw )
TypeError: an integer is required



 So ... please ... any idea on how to convert my "python object" array
of lists to a bidimensional array and how to use it to index [y][x]
elements, or even resize it with the ResizeWidth() and Height()
functions?

 Thanks everybody.


PS: Please, think that I come from C/C++ so I still have some "C ways
of doing things" while there are better/faster ways to do the same in
Python. Feel free also to correct any "C-Style" programming way that
you can find in my source code above... :-)