  Although the two-loop renormalization group equations for a general gauge
field theory have been known for quite some time, deriving them for specific
models has often been difficult in practice. This is mainly due to the fact
that, albeit straightforward, the involved calculations are quite long, tedious
and prone to error. The present work is an attempt to facilitate the practical
use of the renormalization group equations in model building. To that end, we
have developed two completely independent sets of programs written in Python
and Mathematica, respectively. The Mathematica scripts will be part of an
upcoming release of SARAH 4. The present article describes the collection of
Python routines that we dubbed PyR@TE which is an acronym for "Python
Renormalization group equations At Two-loop for Everyone". In PyR@TE, once the
user specifies the gauge group and the particle content of the model, the
routines automatically generate the full two-loop renormalization group
equations for all (dimensionless and dimensionful) parameters. The results can
optionally be exported to Latex and Mathematica, or stored in a Python data
structure for further processing by other programs. For ease of use, we have
implemented an interactive mode for PyR@TE in form of an IPython Notebook. As a
first application, we have generated with PyR@TE the renormalization group
equations for several non-supersymmetric extensions of the Standard Model and
found some discrepancies with the existing literature.
