pyro: A teaching code for computational astrophysical hydrodynamics

We describe pyro: a simple, freely-available code to aid students in learning the computational hydrodynamics methods widely used in astrophysics. pyro  is written with simplicity and learning in mind and intended to allow students to experiment with various methods popular in the field, including those for advection, compressible and incompressible hydrodynamics, multigrid, and diffusion in a finite-volume framework. We show some of the test problems from pyro, describe its design philosophy, and suggest extensions for students to build their understanding of these methods.