Editor features: virtualenvs

Look at the import requests line in your __main__.py file. In your editor, it probably appears with some yellow squiggle underscores, indicating that you won’t have features like auto-complete, jump-to-definition, docs-on-hover, and so on. Or it might be functional, but leaking through to somewhere else in the environment that doesn’t have the same version.

Let’s fix that. Python tooling expects a Virtual Environment (”virtualenv”) which is a specially-constructed folder with a linked Python interpreter, and packages installed in a site-packages subfolder. Since the repository gets the py_binary from aspect_rules_py, it includes a venv target which produces this virtual environment. Run bazel query --output=label_kind app:all to see what targets are available.

py_library rule //app:__test__
_py_pytest_main rule //app:__test___template
determine_main rule //app:_app_bin.find_main
determine_main rule //app:_app_test.find_main
py_binary rule //app:app_bin
py_venv_rule rule //app:app_bin.venv
py_test rule //app:app_test
py_venv_rule rule //app:app_test.venv

app:app_bin.venv is an option, so run that:

% bazel run app:app_bin.venv

Once this has run, the editor should see that a virtualenv now exists in the source folder, and offer to use it to resolve dependencies. Here’s Visual Studio Code with the standard Python extension, for example:

Once you activate this virtualenv, the yellow squiggles should disappear, and you should be able to navigate through the import statement to the requests package.