os-notadirectoryerror-not-a-directory

NotADirectoryError: [Errno 20] Not a directory

Occurs when trying to use a file as if it were a directory.

Reproduce

import os

with open("data.txt", "w") as f:
    f.write("hello")

os.listdir("data.txt")

Error Message

NotADirectoryError: [WinError 267] 디렉터리 이름이 올바르지 않습니다: 'data.txt'

Note: On Unix-based systems, this error may appear as: NotADirectoryError: [Errno 20] Not a directory: 'data.txt'

Fix

import os

os.makedirs("data_dir", exist_ok=True)

print(os.listdir("data_dir"))

Reflection

Tried to treat a file like a folder, but it wasn’t a directory.