Reference library

Testing & modern typing

pytest basics, mocks, type hints, TypedDict, Protocol, and static-checking patterns.

1 match
Testing & modern typing easy

How to Use the pytest tmp_path Fixture for Temporary Directories

Use pytest's built-in tmp_path fixture to create a unique temporary directory per test for clean file I/O testing.

pytest tmp_path fixtures
Python 
import pytest


def test_write_and_read_file(tmp_path):
    # tmp_path is a pytest fixture that provides a temporary directory
    # unique to each test invocation
    data_file = tmp_path / "data.txt"
    data_file.write_text("hello world")
    assert data_file.read_text() == "hello world"


def test_multiple_tmp_pat…
15 0 Open

Browse by section

Each section groups closely related Python snippets.

Testing & modern typing — Python code examples

What you will find here

This page collects testing & modern typing snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.

Samples vs tutorials and challenges

Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.

Related coding tools

Free online Python IDE Write and run Python in your browser — no install. Free Python code formatter Format with autopep8 — side-by-side PEP 8 cleanup. Python code samples Copy-ready snippets to study and run in the IDE.