from PIL import Image

import random

def random_color():
    '''Returns a random RGB three-tuple, where each element of
    the tuple is a random value from the inclusive interval 0 ... 255.
    '''
    redness= random.randrange(0,256)
    greenness = random.randrange(0,256)
    blueness= random.randrange(0,256)
    RGB = (redness, greenness, blueness)
    return RGB

def get_width(drawing):
    '''Returns the width of the Image represented by drawing'''
    width,height = drawing.size
    w = width
    return w

def get_height(drawing):
    '''Returns the height of the Image represented by drawing'''
    width,height = drawing.size
    h = height
    return h

def left(spot):
    '''Returns the coordinate immediately left of spot;
    that is, its x-coordinate is one less than that of spot
    and its y-coordinate is the same as that of spot.
    '''
    (spotx, spoty) = spot
    lspotx = spotx - 1
    lspoty = spoty
    lspot = (lspotx,lspoty)
    return lspot

def right(spot):
    '''Returns the coordinate immediately right of spot;
    that is, its x-coordinate is one greater than that of spot
    and its y-coordinate is the same as that of spot.
    '''
    (spotx, spoty) = spot
    rspotx = spotx + 1
    rspoty = spoty
    rspot = (rspotx, rspoty)
    return rspot

def above(spot):
    '''Returns the coordinate immediately above spot;
    that is, its x-coordinate is the same as that of spot
    and its y-coordinate is one less than that of spot.
    '''
    (spotx, spoty) = spot
    aspotx = spotx
    aspoty = spoty - 1
    aspot = (aspotx, aspoty)
    return aspot

def below(spot):
    '''Returns the coordinate immediately above spot;
    that is, its x-coordinate is the same as that of spot
    and its y-coordinate is one greater than that of spot.
    '''
    (spotx, spoty) = spot
    bspotx = spotx
    bspoty = spoty + 1
    bspot = (bspotx, bspoty)
    return bspot

def is_inbounds( drawing, spot ):
    '''Returns True or False whether coordinate spot is inbounds
    on the Image represented by drawing
    '''
    (spotx, spoty) = spot
    if spotx <0 or spoty <0:
        return False
    if spotx >= get_width(drawing):
        return False
    if spoty >= get_height(drawing):
        return False
    else:
        return True

def get_color( drawing, spot ):
    '''If coordinate spot is inbounds on the Image represented by drawing,
    the function returns the color at spot in the drawing;
    otherwise, the function returns None
    '''
    if is_inbounds(drawing, spot) == True:
        return drawing.getpixel(spot)
    else:
        return None

def is_colorable(drawing, spot, bg=(255,255,255)):
    '''Returns True or False whether coordinate spot is a colorable pixel
    on the Image represented by drawing.
    To be colorable spot must be inbounds and equal to the background color bg.
    '''
    if is_inbounds(drawing, spot) == True:
        if get_color(drawing, spot) == bg:
            return True
    else:
        return False

def paint( drawing, spot, c, bg=(255,255,255) ):
    if is_colorable(drawing, spot, bg=(255,255,255)) == False:
        pass
    else:
        c = drawing.putpixel(spot, get_color(drawing, spot))
    return

if __name__ == '__main__':
    import url_to_image
    link = input( 'Enter web picture location: ' )
    original = url_to_image.get( link )
    image = paint(original, (6,6), random_color(), bg=(255,255,255) )
    image.save( 'img-paint.png', 'PNG' )