Testing & modern typing
pytest basics, mocks, type hints, TypedDict, Protocol, and static-checking patterns.
How to Share Fixtures Across Tests with pytest conftest
Learn how to define pytest fixtures in conftest.py and control their scope (function, module, session) so every test in a directory reuses the same setup and teardown.
import pytest
@pytest.fixture
def sample_data():
"""Simple fixture available to all tests in this directory."""
return {"name": "Alice", "age": 30}
@pytest.fixture(scope="session")
def session_data():
"""Fixture created once per test session."""
return {"session_id": 12345}
@pytest.fixture(scope="mo…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.
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…Browse by section
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Testing & modern typing — Python code examples
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