  We present a fast and user friendly exoplanet transit light curve modelling
package PyTransit, implementing optimised versions of the Gimen\'ez and the
Mandel & Agol transit models. The package offers an object-oriented Python
interface to access the two models implemented natively in Fortran with OpenMP
parallelisation. A partial OpenCL version of the quadratic Mandel-Agol model is
also included for GPU-accelerated computations. The aim of PyTransit is to
facilitate the analysis of photometric time series of exoplanet transits
consisting of hundreds of thousands of datapoints, and of multi-passband
transit light curves from spectrophotometric observations, as a part of a
researcher's programming toolkit for building complex, problem-specific,
analyses.
