Development setup

This document describes the existing developer tooling we have in place (and what to expect of it).

Environment Setup

Follow the Installation steps to prepare the source code. Then follow the steps below to set up the corresponding development environment.

Visual Studio Code

  1. Click on the Python version at the bottom left of the editor’s window and select the Python interpreter which Poetry just created. If you do not find it, check FAQ and troubleshooting for extra instructions. This step is important because it ensures that the current workspace uses the correct Poetry virtual environment which provides all dependencies required.

  2. You can copy the settings below into .vscode/settings.json.

       "markdown.extension.toc.levels": "2..6",
       "python.analysis.typeCheckingMode": "strict",
       "python.formatting.provider": "black",
       "python.linting.enabled": true,
       "python.linting.flake8Enabled": true,
       "python.linting.mypyEnabled": true,
       "python.linting.pylintEnabled": false,
       "editor.formatOnSave": true,
       "python.linting.mypyArgs": [
       "python.sortImports.path": "isort",
       "editor.codeActionsOnSave": {
          "source.organizeImports": true
       "python.analysis.useLibraryCodeForTypes": false,
       "python.analysis.autoImportCompletions": false,
       "files.eol": "\n",
       "": {
          "mypypath": "${workspaceFolder}\\typings"
       "python.analysis.diagnosticSeverityOverrides": {
          "reportUntypedClassDecorator": "none",
          "reportUnknownMemberType": "none",
          "reportGeneralTypeIssues": "none",
          "reportUnknownVariableType": "none",
          "reportUnknownArgumentType": "none",
          "reportUnknownParameterType": "none",
          "reportUnboundVariable": "none",
          "reportPrivateUsage": "none",
          "reportImportCycles": "none",
          "reportUnnecessaryIsInstance": "none",
          "reportPrivateImportUsage": "none",
          "reportUnusedImport": "none",
          "reportUnusedFunction": "none",
          "reportOptionalMemberAccess": "none"
       "python.analysis.stubPath": "./typings",
       "python.languageServer": "Pylance"
  3. Install extensions.

    • Install Pylance to get best code intelligence experience.

    • Install Rewrap to automatically wrap.

    • If there is need to update the documentation, it is recommended to install Markdown All in One. It helps to maintain the table of contents in the documentation.

    • Install reStructuredText to get a syntax checker for reStructuredText. To preview the document, see Local Documentation.


Use the pyvenv package:

(use-package pyvenv
  :ensure t
  :hook (python-mode . pyvenv-tracking-mode))

Then run M-x add-dir-local-variable RET python-mode RET pyvenv-activate RET <path/to/virtualenv> where the value is the path given by the command above. This will create a .dir-locals.el file as follows:

;;; Directory Local Variables
;;; For more information see (info "(emacs) Directory Variables")

((python-mode . ((pyvenv-activate . "~/.cache/pypoetry/virtualenvs/lisa-s7Q404Ij-py3.8"))))

Other setups

  • Install and enable ShellCheck to find bash errors locally.

Code checks

If the development environment is set up correctly, the following tools will automatically check the code. If there is any problem with the development environment settings, please feel free to submit an issue to us or create a pull request for repair. You can also run the check manually.

  • Black, the opinionated code formatter resolves all disputes about how to format our Python files. This will become clearer after following PEP 8 (official Python style guide).

  • Flake8 (and integrations), the semantic analyzer, used to coordinate most other tools.

  • isort, the import sorter, it will automatically divide the import into the expected alphabetical order.

  • mypy, the static type checker, which allows us to find potential errors by annotating and checking types.

  • rope, provides completion and renaming support for pyls.

Local Documentation

It’s recommended to build the documentation locally using Sphinx for preview.

To do so, in ./lisa/docs, run

poetry run make html

You can find all generated documents in ./lisa/docs/_build/html folder. Open them with a browser to view.


If there are already generated documents in ./lisa/docs/_build/html, run poetry run make clean to ensure the documentation is clean and not affected by the previous build.

Extended reading