Question

我已经编写了此功能。它采用索引序列和值矩阵。例如，

path=[1, 0, 2]
matr = [[1, 2, 3], [0, 3, 5], [1, 10, 1]]

这意味着我们的距离为m[1][0]+m[0][2] = 0 + 3 = 3。

我有要按距离排序的路径列表。如果需要材料价值怎么办？我尝试这样做：list_of_paths.sort(key=distance(matr))

def distance(path, matr):
dist = 0
    for i in range(len(path)-1):
        dist += matr[path[i]][path[i+1]]
    return dist

Answer 1

您可以使用自定义函数中内置的path来排序zip()列表：

def distance(p):
    matr = [[1, 2, 3], [0, 3, 5], [1, 10, 1]]
    s = 0
    for x, y in zip(p, p[1:]):
        s += matr[x][y]
    return s

path = [[1, 0, 2], [0, 2, 1], [0, 0, 0]]
print(sorted(path, key=distance))

# [[0, 0, 0], [1, 0, 2], [0, 2, 1]]    <- Output
#      2          3          13        <- in the increasing order of distance.

Answer 2

def distance(path):
     # matr available from global name space
    return sum([matr[path[i]][path[i+1]] for i in range(len(path)-1)])

matr = [[1, 2, 3], [0, 3, 5], [1, 10, 1]]
list_of_paths =[[1, 2, 0], [1, 0, 2], [0, 1, 2]]
list_of_paths.sort(key=distance)
print(list_of_paths)

结果：[[1、0、2]，[1、2、0]，[0、1、2]]

如何按键对值矩阵进行排序？

2 个答案: