python - 在 Pandas 中拆分列

Question

所以我有一个看起来像这样的 pandas 专栏:

full_name = pd.Series([
    'Reservoir 1 Compartment 1', 
    'Reservoir 1 Common Inlet', 
    'Reservoir 2 Compartment 1',
    'Vyrnwy Line 2 Balancing Tank 1', 
    'Reservoir 1'
])

我想把它分成两列。预期的输出应如下所示:

[['Reservoir 1', 'Compartment 1'],
 ['Reservoir 1', 'Common Inlet'],
 ['Reservoir 2', 'Compartment 1'],
 ['Vyrnwy Line 2', 'Balancing Tank 1'],
 ['Reservoir 1', None]]

我试过这个:

res_compartment_split = pd.concat([full_name.str.split(r'\s\s*?(?=[A-Z])', expand=True)])

但我得到了这个输出

[['Reservoir 1', 'Compartment 1', None, None],
 ['Reservoir 1', 'Common', 'Inlet', None],
 ['Reservoir 2', 'Compartment 1', None, None],
 ['Vyrnwy', 'Line 2', 'Balancing', 'Tank 1'],
 ['Reservoir 1', None, None, None]]

感谢您的帮助。

Answer 1

尝试以下操作:

import pandas as pd

full_name = pd.Series([
    'Reservoir 1 Compartment 1', 
    'Reservoir 1 Common Inlet', 
    'Reservoir 2 Compartment 1',
    'Vyrnwy Line 2 Balancing Tank 1', 
    'Reservoir 1'
])

res = full_name.str.split('(?<=\d)\s+(?=[A-Z])', expand=True)

输出:

>>> res
               0                 1
0    Reservoir 1     Compartment 1
1    Reservoir 1      Common Inlet
2    Reservoir 2     Compartment 1
3  Vyrnwy Line 2  Balancing Tank 1
4    Reservoir 1              None

正则表达式模式的解释:

• (?<=\d) - 积极的后视:确保在分隔符之前有一个数字，而不消耗它
• \s+ - 分隔符:匹配一个或多个空格
• (?=[A-Z]) - 正向前瞻:确保紧接着有一个字母(A 到 Z)，而不消耗它

使用 regex101.com 查看实际效果.

另外，您可以在这里看到为什么您的模式不起作用:https://regex101.com/r/nSmEEs/1 .