Astro-SCRAPPY: The Speedy Cosmic Ray Annihilation Package in Python. Astro-SCRAPPY is designed to detect cosmic rays in images (numpy arrays), based on Pieter van Dokkum’s L.A.Cosmic algorithm. Much of this was originally adapted from written by Malte Tewes. I have ported all of the slow functions to Cython/C, and optimized where I can. This is designed to be as fast as possible so some of the readability has been sacrificed, specifically in the C code.