def blocks(size, box=(1,1)):
"""
Iterate over a 2D range in 2D increments.
Returns a 4 element tuple of top left and bottom right coordinates.
"""
box = list(box)
pos = [0,0]
yield tuple(pos + box)
while True:
if pos[0] >= size[0]-box[0]:
pos[0] = 0
pos[1] += box[1]
if pos[1] >= size[1]:
raise StopIteration
else:
pos[0] += box[0]
topleft = pos
bottomright = [min(x[1]+x[0],x[2]) for x in zip(pos,box,size)]
yield tuple(topleft + bottomright)
if __name__ == "__main__":
for c in blocks((100,100),(99,10)):
print c
for c in blocks((10,10)):
print c
