在Python中迭代N维

Question

我有一张地图，我们称之为M，其中包含通过N维映射的数据。

# If it was a 2d map, I could iterate it thusly: 
start, size = (10, 10), (3, 3) 
for x in range(start[0], start[0]+size[0]): 
    for y in range(start[1], start[1]+size[1]): 
     M.get((x, y)) 
# A 3d map would add a for z in ... and access it thusly 
M.get((x, y, z)) 
# And so on. 

我的问题是：我如何使一个迭代器可以产生正确的迭代序列？也就是说，给出start, size = (10, 10), (3, 3)它将产生2元组序列(10, 10), (10, 11), (10, 12), (11, 10), (11, 11)等。并且给出start, size = (10, 10, 10), (3, 3, 3)它将产生正确的3元组序列。

是的，我试过自己，但我的头爆炸了。或者我不能证明花时间搞清楚了，尽管它很有趣。随你挑:)

Answer 1

在Python 2.6+：

itertools.product(*[xrange(i, i+j) for i,j in zip(start, size)]) 

Answer 2

随着做你自发电机expreessions：

start, size = (10, 10), (3, 3) 
values2=((x+xd,y+yd) 
     for x,y in (start,) 
     for xr,yr in (size,) 
     for xd in range(xr) 
     for yd in range(yr)) 

for x,y in values2: 
    print x,y 

start, size = (10, 10, 10), (3, 3, 3) 
values3=((x+xd,y+yd, z+zd) 
     for x,y,z in (start,) 
     for xr,yr,zr in (size,) 
     for xd in range(xr) 
     for yd in range(yr) 
     for zd in range(zr)) 

for x,y,z in values3: 
    print x,y,z