Add template Python module and tests

[inoue0426]

Summary

• Add a minimal src/python_dev template package
• Add typed add and divide functions
• Add pytest coverage for normal and error cases

Test intent

This PR is intended to exercise the baseline checks added previously:

make check
pytest
make coverage

Notes

The previous tooling PR was already merged before these template files were added, so this is a follow-up PR that contains only the template Python code and tests.

[gemini-code-assist]

Code Review

This pull request introduces a template Python package with a calculator module implementing addition and division, along with corresponding unit tests. The review feedback suggests raising a standard ZeroDivisionError instead of a ValueError for division by zero to make the API more idiomatic, updating the tests to match this exception, and importing directly from python_dev instead of src.python_dev to properly leverage the src/ layout.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[gemini-code-assist]

In Python, division by zero is conventionally represented by raising a ZeroDivisionError rather than a ValueError. Using the standard built-in exception makes the API more idiomatic and allows callers to handle division errors using standard exception handling.

Suggested change

	ValueError: If denominator is zero.
	"""
	if denominator == 0:
	raise ValueError("denominator must not be zero")
	ZeroDivisionError: If denominator is zero.
	"""
	if denominator == 0:
	raise ZeroDivisionError("denominator must not be zero")

[gemini-code-assist]

Importing from src.python_dev defeats the purpose of using a src/ layout. Tests should import directly from python_dev to ensure they are testing the package as it would be installed by users.

To support this with your current tooling, you can add the following configurations to pyproject.toml:

• Under [tool.pytest.ini_options], add pythonpath = ["src"] so pytest can find the package.
• Under [tool.mypy], add mypy_path = "src" so mypy can resolve the imports.

Suggested change

	from src.python_dev import add, divide
	from python_dev import add, divide

[gemini-code-assist]

Update the test assertion to expect ZeroDivisionError instead of ValueError to align with the idiomatic exception type for division by zero.

Suggested change

	with pytest.raises(ValueError, match="denominator must not be zero"):
	with pytest.raises(ZeroDivisionError, match="denominator must not be zero"):

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: a9ffeaf2fb

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Use one package name so mypy can resolve the module

In this repo, mypy . treats src/python_dev/__init__.py as python_dev, but this import also loads the same file as src.python_dev. With this line present, make check fails at the mypy step before type checking with Source file found twice under different module names: "python_dev" and "src.python_dev", so the required quality workflow is broken even though pytest passes. Use a single module naming scheme, such as making src an explicit package or importing python_dev consistently with the configured path.

Useful? React with 👍 / 👎.