Encountered Error: "No module named 'openvino'." When Running any OpenVINO™ Toolkit Sample or Demo

When running an OpenVINO™ Python* sample, demo, or custom script, the following error is encountered:
No module named 'openvino'.

This error occurs when the OpenVINO™ Python module is not available in the Python* environment used to run the sample or demo.

If OpenVINO™ was installed using a Python package, ensure that OpenVINO is installed in the same Python environment used to execute the script.

Install OpenVINO™ using: pip install openvino

If OpenVINO™ was installed using a legacy installer, initialize the OpenVINO™ environment before running the sample.

For Windows*
Run: <INSTALL_DIR>\openvino_<version>\bin\setupvars.bat

For Linux*, macOS*, and Raspbian*
Run: source /opt/intel/openvino_<version>/bin/setupvars.sh

Run setupvars script for every new terminal because OpenVINO™ toolkit environment variables are removed when the terminal is closed.