rectangle programming task

rectangle.py

import random
# some globals
W = 6

inside = True
outside = False

def interpret(program, inputt):
    T, D, L, R = program
    i, j = inputt
    return i >= T and i <= D and j >= L and j <= R


def is_correct(program, spec):
    for inputt, output in spec:
        if interpret(program, inputt) != output:
            return False
    return True

# visualize a program and a spec
def visualize_spec(prog_str, spec):
    # use matplotlib to draw a WxW grid, put the rectangle and spec points on it
    import matplotlib.pyplot as plt
    import matplotlib.patches as patches
    fig, ax = plt.subplots()
    ax.set_xlim(0, W)
    ax.set_ylim(0, W)
    # flip y axis
    ax.set_ylim(ax.get_ylim()[::-1])
    ax.set_aspect('equal')
    ax.set_title("Program: " + prog_str)

    # set a different title
    T, D, L, R = eval(prog_str)
    rect = patches.Rectangle((L, T), R-L+1, D-T+1, linewidth=1, edgecolor='r', facecolor='none')
    ax.add_patch(rect)
    for (coord, val) in spec:
        if val:
            ax.scatter(coord[1]+0.5, coord[0]+0.5, c='b')
        else:
            ax.scatter(coord[1]+0.5, coord[0]+0.5, c='r')
    plt.show()
    plt.clf()

if __name__ == '__main__':

    # the rectangle in our figure
    rectangle = [1,3,1,4]

    # the mushrooms and grass in our figure
    shroom1, shroom2 = (0,4), (4,1)
    grass1, grass2 = (1,1), (3,3)

    assert interpret(rectangle, grass1) == inside
    assert interpret(rectangle, grass2) == inside
    assert interpret(rectangle, shroom1) == outside
    assert interpret(rectangle, shroom2) == outside
    print ("working as intended !")
    spec = [(shroom1, outside), (shroom2, outside), (grass1, inside), (grass2, inside)]

    shroom_inside1, shroom_inside2 = interpret(rectangle, shroom1), interpret(rectangle, shroom2)
    grass_inside1, grass_inside2 = interpret(rectangle, grass1), interpret(rectangle, grass2)
    print (shroom_inside1, shroom_inside2, grass_inside1, grass_inside2)

    shroom3 = (2,2)
    grass3 = (4,3)
    shroom4 = (5,4)
    spec2 = [(shroom3, outside), (grass3, inside), (shroom4, outside)]

    # let's try to make a rectangle that satisfy this new spec
    rect2 = [1,3,1,4]
    print (is_correct(rectangle, spec2)) # didn't work
    rect3 = [3,4,1,3]
    print (is_correct(rect3, spec2)) # worked okay

    visualize_spec("[1,3,1,4]", spec)