  We develop an open-source python workflow package, $py$GWBSE to perform
automated first-principles calculations within the GW-BSE (Bethe-Salpeter)
framework. GW-BSE is a many body perturbation theory based approach to explore
the quasiparticle (QP) and excitonic properties of materials. The GW
approximation has proven to be effective in accurately predicting bandgaps of a
wide range of materials by overcoming the bandgap underestimation issues of the
more widely used density functional theory (DFT). The BSE formalism, in spite
of being computationally expensive, produces absorption spectra directly
comparable with experimental observations. The $py$GWBSE package achieves
complete automation of the entire multi-step GW-BSE computation, including the
convergence tests of several parameters that are crucial for the accuracy of
these calculations. $py$GWBSE is integrated with $Wannier90$, a program for
calculating maximally-localized wannier functions, allowing the generation of
QP bandstructures. $py$GWBSE also enables automated creation of databases of
metadata and data, including QP and excitonic properties, which can be
extremely useful for future material discovery studies in the field of
ultra-wide bandgap semiconductors, electronics, photovoltaics, and
photocatalysis.
