One useful feature of the Python math module is quick access to mathematical constants. You can make Python more effective as ...

Once you know how to add and use a Python module, you will greatly extend the capabilities of the language. A Python module is an external class or set of functions that exist outside the main file of ...

os.path.join (folder, filename) ensures the path is correct for the system. On Windows, it uses backslashes (reports\summary.txt); on Linux and macOS it uses forward slashes (reports/summary.txt).