What I learned by writing a Python Pull Request for the first time in my life

I haven't touched Python at all, but I happened to upgrade and brush up Kafka extensions for Azure Functions, so I need to update the Python library as part of that. occured.

I had a hard time because I didn't know the language specifications and tools so much, so I want to record what I learned.

• Kafka extension implementation #62

Virtual Environment Since Python 3.4, a mechanism called Virtual Environment is installed as standard. This will separate the environment when you install the library. There is something close to the mechanism of managing the library of npm in node or bundle in Ruby.

Specifically, execute the following command.

$ python -m venv .venv

This will create a directory called .venv. Execute the following command to enable venv.

$ source .venv/bin/activate

This will allow future installations of libraries to be saved under .venv so that python programs can reference the libraries installed under them while .venv is activated. Will be.

setup.py If you want to add a library, add an entry to setup.py. [Repository] I contributed (https://github.com/Azure/azure-functions-python-library/blob/dev/setup.py)

$ python -m pip install -U -e ./[dev\]

This command will also install the dev part of ʻextras_require in setup.py. Note that -U means ʻUpgrade, which updates the package to a newer version. -e means ʻEditable, which makes the installed library editable. It is usually not in an editable format. When debugging a library, you'll want to experiment and see the source, so it's a good idea to add -e`.

setup.py

from setuptools import setup
from azure.functions import __version__


setup(
    name='azure-functions',
    version=__version__,
    description='Azure Functions for Python',
    long_description='Python support for Azure Functions is based on '
                     'Python3.[6|7|8], serverless hosting on Linux and the '
                     'Functions 2.0 and 3.0 runtime. This module provides the '
                     'rich binding definitions for Azure Functions for Python '
                     'apps.',
    author='Microsoft Corporation',
    author_email='[email protected]',
    classifiers=[
        'License :: OSI Approved :: MIT License',
        'Intended Audience :: Developers',
        'Programming Language :: Python :: 3',
        'Operating System :: Microsoft :: Windows',
        'Operating System :: POSIX',
        'Operating System :: MacOS :: MacOS X',
        'Environment :: Web Environment',
        'Development Status :: 5 - Production/Stable',
    ],
    license='MIT',
    packages=['azure.functions'],
    package_data={
        'azure.functions': ['py.typed']
    },
    extras_require={
        'dev': [
            'flake8~=3.7.9',
            'mypy',
            'pytest',
            'requests==2.*',
            'coverage'
        ]
    },
    include_package_data=True,
    test_suite='tests'
)

Lint

I haven't tried it yet, but Python's Lint is quite quirky, so it's a good idea to include Linter.

• Linting Python in Visual Studio Code

PR Python PR for the first time in my life

• Kafka extension implementation #62