python - 如何从 python 列表中获取零值和非零值的索引范围？

Question

我有一个包含零值和非零值的列表。我想根据列表中的元组找到零值和非零值的范围。我正在寻找使用 pythonic 方式的无包解决方案。例如。

a = [ 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   5,  11,  12,
        12,  12,  13,  13,  17,  17,  17,  17,  17,  17,  17,  17,  17,
        25,  42,  54,  61,  61,  68,  73, 103, 115, 138, 147, 170, 187,
       192, 197, 201, 208, 210, 214, 216, 217, 217, 218, 219, 220, 221,
       222, 222, 219, 220, 220, 221, 220, 216, 216, 217, 217, 217, 217,
       216, 216, 216, 209, 204, 193, 185, 177, 161, 156, 143, 110, 103,
        89,  82,  62,  62,  62,  60,  56,  55,  50,  49,  48,  47,  47,
        45,  44,  43,  42,  40,  37,  23,  22,  14,  12,   6,   0,   0,
         0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
         0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   5,
         6,   6,   6,   7,   7,   7,  13,  29,  31,  32,  33,  41,  42,
        43,  43,  44,  44,  44,  44,  44,  60,  70,  71,  72,  88,  95,
       104, 105, 111, 124, 125, 131, 145, 157, 169, 174, 186, 190, 190,
       191, 192, 192, 193, 193, 193, 194, 198, 201, 202, 203, 202, 203,
       203, 203, 203, 203, 203, 197, 195, 186, 177, 171, 154, 153, 148,
       141, 140, 135, 132, 120, 108,  94,  86,  78,  73,  60,  53,  46,
        46,  45,  44,  43,  37,  35,  29,  26,  19,  11,   0]]

输出:idx = [(0,9),(10,101),(102,128),...]

Answer 1

这里是我的建议，没有外部包，简短、易读且易于理解:

# Compute list "b" by replacing any non-zero value of "a" with 1
b = list(map(int,[i != 0 for i in a]))

#Compute ranges of 0 and ranges of 1
idx = []   # result list of tuples
ind = 0    # index of first element of each range of zeros or non-zeros
for n,i in enumerate(b):
    if (n+1 == len(b)) or (b[n] != b[n+1]):
        # Here: EITHER it is the last value of the list 
        #       OR a new range starts at index n+1
        idx.append((ind,n))
        ind = n+1

print(idx)