python 列表/序列格式

Question

我有如下格式的列表列表。

[[1,3],[2,4],[3,1],[4,0],[5,1],[6,0],[7,1],[8,0 ],[9,1],[10,0],[11,3],[12,1],[13,0],[14,1],[15,0],[16,1], [17,0],[18,4],[19,1],[20,0],[21,1],[22,0],[23,1],[24,2],[25 ,0],[26,0],[27,1],[28,0].........]

或者以图形方式我的输入列表是:

[1,3]
    [2,4]
        [3,1]
            [4,0]
        [5,1]
            [6,0]
        [7,1]
            [8,0]
        [9,1]
            [10,0]
    [11,3]
        [12,1]
            [13,0]
        [14,1]
            [15,0]
        [16,1]
            [17,0]
    [18,4]
        [19,1]
            [20,0]
        [21,1]
            [22,0]
        [23,1]
            [24,2]
                [25,0]
                [26,0]
        [27,1]
            [28,0]

在上面的输入中，列表的第一个值(零位置)是项目序列(你可以从上到下看到它们)，第二个值是它有 child 的数量!

我希望我的输出在第三个值(第二个位置)我想要它的父级，如下例所示......

我想得到这样的输出:[[1,3,0],[2,4,1],[3,1,2],[4,0,3],[5,1,2],[6,0,5],[ 7,1,2],[8,0,7],[9,1,2],[10,0,9],[11,3,1],[12,1,11],[13, 0,12],[14,1,11],[15,0,14],[16,1,11],[17,0,16],[18,4,1],[19,1, 18],[20,0,19],[21,1,18],[22,0,21],[23,1,18],[24,2,23],[25,0,24] ,[26,0,24],[27,1,18],[28,0,27].....]

图形方式的期望输出:

[1,3,0]
    [2,4,1]
        [3,1,2]
            [4,0,3]
        [5,1,2]
            [6,0,5]
        [7,1,2]
            [8,0,7]
        [9,1,2]
            [10,0,9]
    [11,3,1]
        [12,1,11]
            [13,0,12]
        [14,1,11]
            [15,0,14]
        [16,1,11]
            [17,0,16]
    [18,4,1]
        [19,1,18]
            [20,0,19]
        [21,1,18]
            [22,0,21]
        [23,1,18]
            [24,2,23]
                [25,0,24]
                [26,0,24]
        [27,1,18]
            [28,0,27]

如何解决？

Answer 1

你可以用这样的迭代器来做:

def add_parent_info(it, parent=0):
    me, num_children = it.next() # For Python 3.x use next(it)
    yield [me, num_children, parent]
    for i in range(num_children):
        for item in add_parent_info(it, me):
            yield item

用法:

>>> a = [[1,3],[2,4],[3,1],[4,0],[5,1],[6,0],[7,1],[8,0],[9,1],[10,0],[11,3],[12,1],[13,0],[14,1],[15,0],[16,1],[17,0],[18,4],[19,1],[20,0],[21,1],[22,0],[23,1],[24,2],[25,0],[26,0],[27,1],[28,0]]
>>> print list(add_parent_info(iter(a)))
[[1, 3, 0], [2, 4, 1], [3, 1, 2], [4, 0, 3], [5, 1, 2], [6, 0, 5], [7, 1, 2], [8, 0, 7], [9, 1, 2], [10, 0, 9], [11, 3, 1], [12, 1, 11], [13, 0, 12], [14, 1, 11], [15, 0, 14], [16, 1, 11], [17, 0, 16], [18, 4, 1], [19, 1, 18], [20, 0, 19], [21, 1, 18], [22, 0, 21], [23, 1, 18], [24, 2, 23], [25, 0, 24], [26, 0, 24], [27, 1, 18], [28, 0, 27]]