Öffnen, lesen, schreiben

with open(filename, "r+") as file:
	if "search pattern" in file.read():
		return file
with open(filename, "a") as file:
	file.write("Append this.")
with open(filename, "w") as file:
	file.writelines("This is written to the file.")

Working with pathlib

import Path from pathlib
# Two parent directories up from this one
two_dirs_up = Path(__file__).resolve().parent.parent
path = Path.home() / "folder" 
# This actually results in "$HOME/folder". I mean... wha-?

Working with os

import os
os.path.join(path, name)
os.listdir(path) # Top level dir
os.walk(path) # Dir and all subdirs

Tips and tricks

is_markdown = filename.endswith(".md")