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).

The example files used here can be downloaded by clicking the file name: example1.txt, example1.csv, example1.xlsx. (For text format files, you can copy the content on the webpage and paste it into a ...

Google Colab is a free online tool from Google that lets you write and run Python code directly in your browser.