* * Demonstrates the syntax for creating a two-dimensional (2D) list, * which, in Python, is simply a list of lists. * Values in a 2D list are accessed through two index values. * 2D arrays are useful for storing images. In this example, each dot * is colored in relation to its distance from the center of the image.
# By convention, Python constants have UPPERCASE_NAMES. SPACER = 10 # Start with an empty list. distances =  def setup(): size(640, 360) maxDistance = dist(width / 2, height / 2, width, height) for x in range(width): column =  distances.append(column) for y in range(height): distance = dist(width / 2, height / 2, x, y) column.append(distance / maxDistance * 255) spacer = 10 noLoop() # Run once and stop def draw(): background(0) # This embedded loop skips over values in the arrays based on # the spacer variable, so there are more values in the array # than are drawn here. Change the value of the spacer variable # to change the density of the points for x in range(0, width, SPACER): for y in range(0, height, SPACER): stroke(distances[x][y]) point(x + SPACER / 2, y + SPACER / 2)