Rediscovering Python's Pathlib

From Type Hint to Power Tool: Python’s Pathlib

For a long time, I used Path from Python’s pathlib module purely as a type hint - a way to make function signatures look more modern and semantically clear. Like this:

from pathlib import Path

def process_file(file_path: Path):
    ...

It changed when I started building an application that handled user-uploaded documents. I had to create temporary folders, write intermediate files, manage output paths, and ensure directories existed before saving results. That’s when Path went from just a type hint to a core part of my file management logic.

Why pathlib is Worth More than a Hint

Here are the use cases where it transformed my workflow:

Ensuring Directories Exist

Before:

import os

if not os.path.exists("output"):
    os.makedirs("output")

Now:

from pathlib import Path

Path("output").mkdir(parents=True, exist_ok=True)

• parents=True: Creates any missing parent directories.
• exist_ok=True: Prevents an error if the directory already exists. This is equivalent to os.makedirs(), but more cleaner and readable!

Managing Directories

While handling temporary files for a file-processing API, I needed to:

• Create a temp folder
• Ensure it exists
• Write intermediate files
• Clean up afterward

With Path, this became natural and structured:

from pathlib import Path

temp_dir = Path("/tmp/myapp") / "job123"
temp_dir.mkdir(parents=True, exist_ok=True)

output_file = temp_dir / "translated.txt"
output_file.write_text("Translated content")

content = output_file.read_text()

• write_text(data: str): Writes a string to a text file (overwrites if it exists).
• read_text(): Reads file content and returns a string.

To cleanup the (temporary) directories:

# Cleanup later if needed
output_file.unlink()
temp_dir.rmdir()

• unlink: Deletes a file
• rmdir: Removes an empty directory

You can use unlink with a parameter missing_ok:

• Without missing_ok=True: raises FileNotFoundError if the file doesn’t exist.
• With missing_ok=True: silently does nothing if the file is already gone.

You can also check path status to avoid runtime errors:

p = Path("result.txt")

p.exists()    # True if file or directory exists
p.is_file()   # True if it's a regular file
p.is_dir()    # True if it's a directory

To list directory contents:

p = Path("my_folder")

for item in p.iterdir():
    print(item)

Path Arithmetic

Joining paths becomes expressive with /:

base = Path("/data")
file = base / "user" / "output.txt"

Compared to:

file = os.path.join("/data", "user", "output.txt")

You can also extract name, stem, suffix (file extension) and so on:

p = Path("/home/user/project/file.txt")

p.name      # 'file.txt'
p.stem      # 'file'
p.suffix    # '.txt'
p.parent    # PosixPath('/home/user/project')
p.parts     # ('/', 'home', 'user', 'project', 'file.txt')