VSCode problem - import could not be resolved from the source (Pylance)

Problem description

In Visual Studio Code (VSCode), I'm working with a Jupyter notebook (.ipynb file) and encountering a linter warning related to the pandas library. Specifically, when I try to import pandas, I see the following warning:

Import "pandas" could not be resolved from the source Pylance

This warning appears as a squiggly underline beneath the import statement, and hovering over it displays the full error message.

Important context: 1. I'm using VSCode as my integrated development environment (IDE). 2. The file I'm working on is a Jupyter notebook, not a regular Python script. 3. I have pandas installed in a virtual environment (virtualenv) that I've set up for this project. 4. Pylance, which is Microsoft's static type checking tool for Python, is raising this warning. 5. Despite the warning, the code runs without errors when I execute the cell. 6. This issue is specifically occurring within the notebook interface in VSCode, not in a regular Python file.

The discrepancy between the successful execution and the linter warning suggests a potential misconfiguration in how VSCode or Pylance is interpreting my project setup, particularly in relation to the virtual environment or the notebook context.

Potential origins and troubleshooting steps

This issue often occurs when VSCode isn't correctly recognizing your virtual environment or the installed packages.

1. VSCode not using the correct Python interpreter:

• Ensure VSCode is using the Python interpreter from your virtualenv.
• Open the Command Palette (Ctrl+Shift+P) and select "Python: Select Interpreter".
• Choose the interpreter from your virtualenv.

2. Virtualenv not activated:

• Make sure your virtualenv is activated in the terminal you're using within VSCode.
• You can activate it manually or set up VSCode to automatically activate it.

3. Pandas not installed in the virtualenv:

• Double-check that pandas is installed in your virtualenv.
• Run pip list in the terminal to verify.

4. Pylance configuration:

• Pylance might not be configured to recognize your virtualenv.
• Check your VSCode settings (settings.json) for Python and Pylance-related configurations.

5. Caching issues:

• Sometimes VSCode or Pylance caches can cause issues.
• Try reloading the VSCode window (Ctrl+Shift+P, then "Developer: Reload Window").

Options for fixing the problem:

1. Manually select the correct interpreter: Use the "Python: Select Interpreter" command as mentioned above.

2. Configure python.pythonPath: In settings.json, set "python.pythonPath" to the path of your virtualenv's Python executable.

3. Create a .env file: In your project root, create a .env file with PYTHONPATH=/path/to/your/virtualenv/lib/python3.x/site-packages.

4. Update Pylance settings: In settings.json, add or update: json "python.analysis.extraPaths": ["/path/to/your/virtualenv/lib/python3.x/site-packages"]

5. Reinstall pandas: Activate your virtualenv and run pip uninstall pandas followed by pip install pandas.

6. Update VSCode and extensions: Ensure VSCode and the Python extension are up to date.

If you've tried these steps and still face issues, you might want to check for any conflicting extensions or consider creating a new virtualenv to rule out environment-specific problems.