Python Import Path Mismatch Debugging When a ModuleNotFoundError occurs for an installed package, the issue is often an environment or path mismatch rather than a missing installation. Check: (1) which Python interpreter the CLI/script is using via or shebang lines, (2) confirm the package is installed in that specific environment with , and (3) verify the active virtual environment matches where the package was installed. Use to trace which environment Python is actually loading from. ---