  The characterization of exoplanet requires reliable determination of the
fundamental parameters of their host stars. Spectral fitting plays an important
role in this process. For the majority of stellar parameters matching synthetic
spectra to the observations provides a robust and unique solution for
fundamental parameters, such as effective temperature, surface gravity,
abundances, radial and rotational velocities and others. Here we present a new
software package for fitting high resolution stellar spectra that is easy to
use, available for common platforms and free from commercial licenses. We call
it PySME. It is based on the proven Spectroscopy Made Easy (later referred to
as IDL SME or "original SME") package. The IDL part of the original SME code
has been rewritten in Python, but we kept the efficient C++ and FORTRAN code
responsible for molecular-ionization equilibrium, opacities and spectral
synthesis. In the process we have updated some components of the optimization
procedure offering more flexibility and better analysis of the convergence. The
result is a more modern package with the same functionality of the original
SME. We apply PySME to a few stars of different spectral types and compared the
derived fundamental parameters with the results from IDL SME and other
techniques. We show that PySME works at least as well as the original SME.

Solar and Stellar Astrophysics;Earth and Planetary Astrophysics;Instrumentation and Methods for Astrophysics