Slides to support revision of iteration and lead to the reading of CSV files. In Python, CVS files are a no brainer because of the built-in library. What pupils find challenging though, is the data from CSV files, namely, 2d lists (aka nested lists, lists of lists, lists of records). I find when teaching CSV having to go back and revisit various types of loops, especially nested loops. Unless pupils understand nested loops, they won't be able to use CSV confidently.
PowerPoint format with screenshots, copy and paste Python code and screen capture videos.