See the tar file below for a fast transit light curve code written in Python, with heavy lifting done by C extensions. The code uses a quadratic limb darkening law and is based on the original Fortran version provided by Mandel & Agol (2002). It provides more than an order of magnitude speed-up over a pure Python version. The directory contains a README file with instructions on compilation and an example code, demo.py. If you use the code, please send me your contact information so I can alert you to bug fixes or other improvements. 8/21/14:
Correction to handle the corner case (z,p) = (0.5, 0.5). Thanks to Ethan Kruse for catching it!