Python os.walk

In my processing of OS OpenData into a useful format, I realized that I needed to traverse a lot of directories from a root folder in order to get to the files I wanted, as each map tile is contained in its own folder and these tiles are spread across a number of data CDs. The solution, as with many things in GIS, is to use Python, or more specifically the OS.Walk module.

The module returns a triplet of values: a string for the current directory, a list of the directories within the walked path and a list of the files within the walked path. As with all tuples/triplets these can be iterated through using for loops to access the files and folders at each stage of the walk.

The syntax for this is as follows:


Which will iterate through the files and folders in the provided path and print the paths, directories and files to the screen. From here it is possible to test for files of a particular extension or filename by replacing the print statements with conditional statements or other operations.