ModuleNotFoundError: No module named

Problem

You receive the error ModuleNotFoundError: No module named when you deploy an app on Streamlit Community Cloud.

Solution

This error occurs when you import a module on Streamlit Community Cloud that isn’t included in your requirements file. Any external Python dependencies that are not distributed with a standard Python installation should be included in your requirements file.

E.g. You will see ModuleNotFoundError: No module named 'sklearn' if you don’t include scikit-learn in your requirements file and import sklearn in your app.