The Python interpreter is the executable that runs your code. VS Code can display one interpreter while the terminal uses another, which is why a package may appear installed but still produce an import error. The solution is to make the project environment explicit.
Create a virtual environment inside the project, then select it through the editor’s interpreter control. Open a new terminal after switching environments and verify the executable path. Run a small script that prints the Python version and imports one project dependency. The run command, debugger, test runner, and terminal should all point to the same environment.
If the selection keeps changing, inspect workspace settings and remove stale interpreter paths. Do not solve every problem by installing packages globally. Global installations hide environment mistakes and make projects difficult to reproduce. A documented setup file, a dependency declaration, and a short verification command give teams a more reliable development workflow.