Error: os.listdir()

[vezycash]

https://github.com/thewhitetulip/build-app-with-python-antitextbook/blob/master/01-intro-to-python.md#example-list-all-txt-files

import os
files = os.listdir()
for file in files:
    if file.endswith(".txt"):
        print(file)

Function os.listdir() expects an argument (a folder name)

files = os.listdir("folder")

folder = the folder which contains the text files.

OR
files=os.listdir(".")
//In this case, the files have to be in the same directly as file.py

[Suraj Patil]

Actually, since pytjon3 it accepts zero arguments, if there is no argument, it lists the current directory

[vezycash]

You're right.