Pyclaw is a Python-based solver for hyperbolic PDEs that includes the algorithms of Clawpack and SharpClaw. It has been designed with easy extensibility, performance, and exploration in mind. The high-level code is written in Python using numpy and based on the PyClaw package. The low-level kernels used are the Clawpack and SharpClaw routines, which are written in Fortran. The PyClaw package also includes a scalable parallel implementation of Clawpack and SharpClaw, using PETSc.