The Shapely and Fiona libraries have been introduced in Chapter 2, Introduction to Geospatial Code Libraries, in the sections Shapely and Fiona. It makes sense to cover both of them together, as Shapely depends on other libraries for reading and writing files and Fiona fits the bill. As we'll see in the examples, we can use Fiona to open and read files and then pass geometry data to Shapely objects.