Create a Python development environment in 10 minutes (Mac OS X + Visual Studio Code)

Make a note as a memorandum.

reference

I referred to the following article.

Qiita: Python environment construction on Mac

Overview

With the goal of installing the following and debugging on VS Code, The procedure is described below.

• Python3 latest version
• pyenv-virtualenv
• flake8
• yapf
• mypy

Install pyenv-virtualenv

pyenv-virtualenv is a tool that manages the version of the operating environment, like rbenv in ruby and nvm in node.js. Not only is it easy to switch versions for each application, but it is also possible to create virtual environments within the same version.

• Install from brew $ brew install pyenv-virtualenv

• Add the following to bash_profile vi ~/.bash_profile

export PYENV_ROOT=/usr/local/var/pyenv
if which pyenv > /dev/null; then eval "$(pyenv init -)"; fi
if which pyenv-virtualenv-init > /dev/null; then eval "$(pyenv virtualenv-init -)"; fi

Reflect the settings and check if it works properly

$ source ~/.bash_profile
$pyenv

Latest Python installation

• Get a list of installable Python versions $ pyenv install --list

• Install the latest version as of the time of writing the article $ pyenv install 3.5.2

• Update the global environment after the installation is complete $ pyenv global 3.5.2

• Just in case, make sure that the python version is set to global $ python --version

Create working folder

Create a virtual environment with pyenv-virtual and apply it to the created working folder.

• Create environment name ʻenv_352based on current environment$ pyenv virtualenv 3.5.2 env_352`

$ mkdir dev
$ cd dev

• Set the operating environment of the working folder to ʻenv_352 $ pyenv local env_352`

installation of flake8

flake8 is Python's Linter. pip install flake8

yapf yapf is a Python code formatting tool. pip install yapf

mypy mypy is a code analysis tool. It does type checking statically like Typescript. I personally feel relieved to have it, so I will introduce it. pip install mypy

Visual Studio Code settings

• Move to the folder to develop
• Press Ctrl + Shift P and enter ʻExtensions: Install Extensions`
• Search for Python and install the top hits
• Open Code → Preferences → Workspace Settings at the top left of the screen and add the following items

python

{
   "python.linting.flake8Enabled": true,
   "python.formatting.provider": "yapf",
   "python.linting.mypyEnabled": true
}

Open the debug screen with Cmd + Shift + D, click the gear mark on the upper left, and click To add an item to test the currently open file, add the following description.

python

{
		"name": "Test This",
		"type": "python",
		"request": "launch",
		"stopOnEntry": false,
		"pythonPath": "${config.python.pythonPath}",
		"program": "${file}",
		"debugOptions": [
			"WaitOnAbnormalExit",
			"WaitOnNormalExit",
			"RedirectOutput"
		]
	}

Operation check

• Create a new tab and save it in py format. Write as follows and press F5 to confirm that it is displayed normally in the Debug Console.

print('Hello, World')

• Confirm that mypy, flake8 gives an error when saving after writing incorrectly
• Select a code → right click → Format Code to confirm that the file is formatted