Python File and Directory Operations

A Path represents a location on disk. Joining with / uses the correct separator on every operating system, so the same code works on Windows (\) and macOS or Linux (/):

from pathlib import Path
project = Path("projects") / "regatta" / "photos"
print(project.name, project.parent, project.suffix)   # photos projects/regatta (empty)
image = project / "finish-line.png"
print(image.stem, image.suffix)                       # finish-line .png

Useful attributes and methods include .name, .stem, .suffix, .parent, .exists(), .is_file(), .is_dir(), .resolve() (absolute path) and Path.home() and Path.cwd().

Creating a Path object doesn't touch the disk; it's only a description of a location. Path("missing.txt") is a perfectly valid object for a file that doesn't exist. Check with .exists(), or just try the operation and handle the error. Older code uses os.path.join() and string paths; they still work, and most functions accept either form.

mkdir() creates a folder. Two options make it practical:

archive = Path("archive") / "2026" / "july"
archive.mkdir(parents=True, exist_ok=True)

• parents=True creates any missing parent folders, like mkdir -p.
• exist_ok=True makes it succeed quietly if the folder is already there, so the script can run repeatedly.

Without exist_ok, an existing folder raises FileExistsError. Even with it, if a file (not a folder) already has that name, mkdir still fails, because a file can't be turned into a directory.

For scratch work, tempfile.TemporaryDirectory() creates a unique folder and deletes it, with everything inside, when the with block ends. It's the safest place for tests, experiments and intermediate files.

Three methods list a folder's contents:

pngs = sorted(p for p in archive.glob("*.png") if p.is_file())
total = sum(p.stat().st_size for p in pngs)

Patterns use * (any characters), ? (one character) and [abc] (one of a set); ** in glob() means "any depth of folders". All three return iterators, and the order is not guaranteed: it depends on the operating system and file system. Sort the results whenever order matters for display, reproducibility or tests.

os.walk() is the older alternative that yields each folder with lists of its sub-folders and files, which is still handy when you need to process a tree folder by folder.

rename() may fail across different drives; shutil.move() handles that case by copying and deleting.

Before any recursive delete, check the target: print it, make sure it's inside the folder you expect (target.resolve().is_relative_to(base.resolve()) in Python 3.9+), and never build it from unchecked user input. Scripts that delete things are often run with a "dry run" option first, which prints what would be removed without doing it.

Task: create and rename sample files inside TemporaryDirectory, then explain the difference between unlink and rmdir.

from pathlib import Path
from tempfile import TemporaryDirectory

with TemporaryDirectory() as tmp:
    folder = Path(tmp) / "drafts"
    folder.mkdir()
    draft = folder / "draft.txt"
    draft.write_text("v1", encoding="utf-8")
    final = draft.rename(folder / "final.txt")
    print(sorted(p.name for p in folder.iterdir()))   # ['final.txt']
    final.unlink()          # removes a file
    folder.rmdir()          # removes an empty directory
    print(folder.exists())  # False

unlink() deletes a file; rmdir() deletes a folder only when it's empty, which is why the file had to go first. For the worked check: does creating a Path object create a filesystem entry? No. Only methods such as mkdir(), touch() or write_text() change the disk.

The pathlib documentation and shutil documentation cover every operation, including the table mapping os.path functions to pathlib. Continue with the standard library tour and environment configuration. Practise with the Python exercises and Python quiz.