Statistics, Data Mining, and Machine Learning in Astronomy A An Introduction to Scientific Computing with Python “The world’s a book, writ by the eternal art – Of the great author printed in man’s hea[.]
A An Introduction to Scientific Computing with Python “The world’s a book, writ by the eternal art – Of the great author printed in man’s heart, ’Tis falsely printed, though divinely penned, And all the errata will appear at the end.” (Francis Quarles) n this appendix we aim to give a brief introduction to the Python language1 and its use in scientific computing It is intended for users who are familiar with programming in another language such as IDL, MATLAB, C, C++, or Java It is beyond the scope of this book to give a complete treatment of the Python language or the many tools available in the modules listed below The number of tools available is large, and growing every day For this reason, no single resource can be complete, and even experienced scientific Python programmers regularly reference documentation when using familiar tools or seeking new ones For that reason, this appendix will emphasize the best ways to access documentation both on the web and within the code itself We will begin with a brief history of Python and efforts to enable scientific computing in the language, before summarizing its main features Next we will discuss some of the packages which enable efficient scientific computation: NumPy, SciPy, Matplotlib, and IPython Finally, we will provide some tips on writing efficient Python code Some recommended resources are listed in §A.10 I A.1 A Brief History of Python Python is an open-source, interactive, object-oriented programming language, created by Guido Van Rossum in the late 1980s Python is loosely based on the earlier ABC, a language intended to be taught to scientists and other computer users with no formal background in computer science or software development Python was created to emulate the strengths of ABC—its ease of use, uncluttered syntax, dynamic typing, and interactive execution —while also improving on some of ABC’s weaknesses It was designed primarily as a second language for experienced programmers—a full-featured scripting framework to “bridge the gap between the shell and C.”2 But because of its heritage in ABC, Python quickly became a popular language choice for introductory programming courses, as well as for nonprogrammers who require a computing tool Increasingly, the same beauty and ease of use that http://python.org Guido Van Rossum, “The Making of Python,” interview available at http://www.artima.com/ intv/pythonP.html; accessed October 2012