pathlib

Difficulty
Path(s)	Stdlib Deep Dives
Prereqs	Basic Python
Unlocks	caching, zipapp
Repo	pysprings/lightning-talks/pathlib

Overview

Modern, object-oriented file path handling with Python's pathlib module (stdlib since Python 3.4). Replaces the older os.path functional approach with a cleaner API.

Key Concepts

• Path objects replace string-based paths — use / operator instead of os.path.join()
• Cross-platform by default — no need to worry about path separators
• Built-in file operations — Path.read_text(), Path.write_text(), Path.glob()
• Rich attribute access — .name, .suffix, .parent, .stem

The Code

pathlib/README.md — Full comparison of os.path vs pathlib

Before (os.path)

import os.path

fname = os.path.join(".", "test.py")
os.path.abspath("../../test.py")
os.path.basename("../../test.py")
os.path.splitext("test.py")

After (pathlib)

from pathlib import Path

fname = Path(".") / "test.py"
Path("../../test.py").resolve()
Path("../../test.py").name  # "test.py"

# Glob returns a generator
all_python_files = Path(".").glob("**/*.py")

# Direct file I/O — no open() needed
Path("myfile.md").write_text("# Here's a title!")

Try It

1. Open a Python REPL
2. Try these one-liners:

   from pathlib import Path
   print(list(Path(".").glob("*.py")))       # find all .py files
   print(Path(__file__).parent.resolve())     # directory of current script
   

3. Challenge: Rewrite a script that uses os.path.join and os.path.exists to use pathlib instead

Further Reading

• pathlib docs
• os.path → pathlib correspondence table

Where to Go Next

• caching — Optimize function performance with functools.lru_cache
• zipapp — Package your Python app as a single .pyz file (uses pathlib for file handling)