You can’t do much if you cannot read and write all the different kinds of file formats commonly used in astronomy. After mastering this tutorial, you will be able to read and write most of the common dataformats yourself, and at least know where to start to read and write the more obscure ones.
These notes are based on the the reading/writing tutorial (written by Thomas Robitaille and Rory Holmes) of the python4mpia and python4ESAC and the scipy-lectures on Python.