Initialize 2D list

Initializes a 2D list of given width and height and value.

• Use a list comprehension and range() to generate h rows where each is a list with length h, initialized with val.
• Omit the last argument, val, to set the default value to None.

def initialize_2d_list(w, h, val = None):
  return [[val for x in range(w)] for y in range(h)]

initialize_2d_list(2, 2, 0) # [[0, 0], [0, 0]]