使用 pathlib 和 for 循环重命名文件夹中的文件

Question

I've written the following renaming tool in Python. It was unintentionally moving all my files to a single directory until I added the os.chdir in my for loop, which then made it work better and keep each renamed file inside its correct folder. But I don't really understand the logic behind why this script, without the os.chdir, was moving all my files to a single directory, can somebody help me understand? Thank you.

import pathlib
from pathlib import Path
import os

folderDir = Path(input("Please enter the parent directory: \n"))

folderList = [folder for folder in folderDir.iterdir() if folder.is_dir()]

for f in folderList:
    
    fileList = [e for e in f.iterdir() if e.is_file()]

    os.chdir(f)

    count = 1
    for i in fileList:
        folderName = os.path.basename(os.path.dirname(i))
        i.rename(folderName + "_" + str(count).zfill(3) + pathlib.Path(i).suffix)
        count += 1

Answer 1

I would assume this is because it was renaming the files to your current working directory (ie wherever you saved the script) rather than the actual directory where the files were stored.

file = your/file/name.txt
os.path.dirname(file) # This gives 'your/file'
os.path.basename(your/file) # This gives 'file'

The script was therefor creating a folder called 'file' in the example above in your cwd. By adding in the chdir(f), it creates in this directory instead as this already exists it modifies the existing file. Which is what you want.

I may be wrong but that it is my understanding. I hope this makes sense.