创建helper列有助于获取文件和目录的计数

import pandas as pd

splits = df['FilePath'].str.split('\\')
df['Hierarchy'] = splits.str[1:-1].str.join(' > ')

# Before/Final is before the last directory
df['Before/Final'] = splits.str[-3]

# Final/Dir is the last directory
df['Final/Dir'] = splits.str[-2]

# FileCnt is the number of files in the last directory (number of times it's Final/Dir appears in the column)
df['FileCnt'] = df.groupby('Final/Dir')['Final/Dir'].transform('count')

# Create a dictionary of the number of directories in the last directory {Final/Dir: DirCnt}
dir_cnt = df.groupby('Before/Final')['Final/Dir'].nunique().to_dict()

# DirCnt is the number of directories in the last directory, if it's not in the dictionary then it's 0
df['DirCnt'] = df['Final/Dir'].map(dir_cnt).fillna(0).astype(int)

# you can delete the columns you don't need
df.drop(['Before/Final', 'Final/Dir'], axis=1, inplace=True)

额外的列：
| 文件路径|层级|之前/最终|最终/指导|文件计数|直接计数|
| - ------| - ------| - ------| - ------| - ------| - ------|
| 文件夹：\colab\a. csv|科拉布|史：|科拉布|三个|1个|
| 文件夹：\colab\b. csv|科拉布|史：|科拉布|三个|1个|
| 文件夹：\colab\c. csv|科拉布|史：|科拉布|三个|1个|
| S:\colab\apple\dog.txt|可乐〉苹果|科拉布|苹果|第二章|无|
| S:\colab\apple\cat.pdf|可乐〉苹果|科拉布|苹果|第二章|无|
dir_cnt字典：
| 最终/指导|直接计数|
| - ------| - ------|
| 史：|1个|
| 科拉布|1个|