Fix Pylance resolveMissingImports in VS Code

David Y.

—July 15, 2024

The Problem

Whenever I try to import a package in my Python script, Visual Studio Code underlines it in yellow and displays an error like this:

Import "fastapi" could not be resolved Pylance(resolveMissingImports)

I’ve already set up a virtual environment and installed the package with PIP by running this command in the VS Code terminal:

pip install fastapi

Why is it still showing up as missing? I’m using Visual Studio Code on Windows.

The Solution

Before you can run scripts in a Python virtual environment, you must first activate that environment. You can do this by following these steps:

1. Open the Command Palette (Ctrl+Shift+P).
2. Begin typing “Python” and choose the option “Python: Select Interpreter” when it appears.
3. Select the Python interpreter in your virtual environment – it should be the top option, with a “Recommended” tag.

If you previously installed fastapi to the virtual environment, the resolveMissingImports error should now disappear. Otherwise, run pip install fastapi in your terminal before attempting to run your Python script.

Configure VS Code to automatically activate the virtual environment for your current project in its embedded terminal by following these steps:

1. Navigate to File > Preferences > Settings. This will open the VS Code settings page.
2. Search “Python” in the search bar near the top of the Settings page.
3. Find and check the box under Python > Terminal > Activate Environment.

After enabling this option, whenever you open a Python file in VS Code, the editor’s integrated terminal will automatically activate the virtual environment in the current workspace. Per the documentation, if no workspace-specific virtual environment is found, it will look for a global Pipenv or Poetry environment, and then for a globally installed version of Python.