python - 列表列表中的非规范化层次结构

Question

我正在解析一个文件，其中标签定义如下，并使用换行符表示层次结构

+--------------------+--------------------+--------------------+
| L1 - A             |                    |                    |
|                    |  L2 - B            |                    |
|                    |                    |  L3 - C            |
|                    |                    |                    |
| L1 - D             |                    |                    |
|                    |  L2 - E            |                    |
|                    |                    |  L3 - F            |
+--------------------+--------------------+--------------------+

我将以上表示为:

labels = [
   ['A', None, None, None, 'D', None, None],
   [None, 'B', None, None, None, 'E', None],
   [None, None, 'C', None, None, None, 'F']
]

我试过了

def joinfoo(items):
   if len(items) == 1:
      return items[0]

   result = []
   active = None
   for x, y in zip(items[0], joinfoo(items[1:])):
      active = x if x else active
      if type(y) is tuple:
         result.append((active, y[0], y[1]))
      else:
         result.append((active, y))

   return result

我想要

[
   ('A', None, None), ('A', 'B', None), ('A', 'B', 'C'),
   (None, None, None),
   ('D', None, None), ('D', 'E', None), ('D', 'E', 'F')
]

得到了这个

[
   ('A', None, None), ('A', 'B', None), ('A', 'B', 'C'),
   ('A', 'B', None),
   ('D', 'B', None), ('D', 'E', None), ('D', 'E', 'F')
]

有关如何修复 joinfoo() 以达到预期结果的建议？解决方案需要支持可变数量的列。

它应该类似于 for x, y in zip(joinfoo(items[:-1]), items[-1]): 而不是 for x, y in zip (items[0], joinfoo(items[1:])): 朝正确的方向前进...？

编辑:原始的列表列表可能错误地暗示了层次结构的模式。没有明确的模式。列数也是可变的。也许是一个更好的测试用例..

+--------------+--------------+--------------+
|   L1 - A     |              |              |    = A
|              |    L2 - B    |              |    = A - B
|              |              |    L3 - C    |    = A - B - C
|              |              |    L3 - D    |    = A - B - D
|              |    L2 - E    |              |    = A - E
|              |              |              |    =   
|   L1 - F     |              |              |    = F
|              |    L2 - G    |              |    = F - G
|              |              |    L3 - H    |    = F - G - H
+--------------+--------------+--------------+

labels = [
   ['A', None, None, None, None, None, 'F', None, None],
   [None, 'B', None, None, 'E', None, None, 'G', None],
   [None, None, 'C', 'D', None, None, None, None, 'H']
]

Answer 1

我花了一些时间，想知道如何解决这个问题。

这是我的解决方案，也许它会激发一些想法:

labels = """\
+--------------------+--------------------+--------------------+
| L1 - A             |                    |                    |
|                    |  L2 - B            |                    |
|                    |                    |  L3 - C            |
|                    |                    |                    |
| L1 - D             |                    |                    |
|                    |  L2 - E            |                    |
|                    |                    |  L3 - F            |
+--------------------+--------------------+--------------------+
"""

lines = [[(s.strip()[-1:] if s.strip() else None)
             for s in line[1:-1].split('|')]
                 for line in labels.splitlines()[1:-1]]

for index, labels in enumerate(lines):
    if not any(labels):
        continue
    for i, label in enumerate(labels):
        if label:
            break
        if not label:
            lines[index][i] = lines[index-1][i]

print([tuple(labels) for labels in lines])

# --> [('A', None, None), ('A', 'B', None), ('A', 'B', 'C'), (None, None, None), ('D', None, None), ('D', 'E', None), ('D', 'E', 'F')]