task15.py

from functools import reduce
from PIL import Image

l = [[i, i - 1, i - 1, 1 - 2] for i in range(100, 1, -2)]
l = reduce(lambda x, y: x + y, l)
# print(l, len(l))

org = Image.open('wire.png')
org_data = list(org.getdata())
res = Image.new(org.mode, (100, 100))
res_data = res.load()

# (0,0)
#    ---->x
#    |
#    vy
dire = [(1, 0),  # > (x+1, y) right
        (0, 1),  # v (x, y+1) down
        (-1, 0),  # < (x-1, y) left
        (0, -1),  # ^ (x, y-1) up
        ]

# init        
v = 0
org_index = 0
res_pos = (-1, 0)

for times in l:
    for i in range(times):
        # pos will out of index if reset position after setting color
        # (res_pos[0] + dire[v][0], res_pos[1] + dire[v][1])
        res_pos = tuple(map(lambda x, y: x + y, res_pos, dire[v]))

        # f = open('level14.d/log.log','a')
        # print >> f, pos
        # f.close()

        res_data[res_pos] = org_data[org_index]
        org_index += 1

    v = (v + 1) % 4  # j + 1 if j != 4 else 0

res.save('res.png')