The Python QSO fitting code (PyQSOFit) measures spectral properties of quasars. Based on Shen's IDL version, this code decomposes different components in the quasar spectrum, e.g., host galaxy, power-law continuum, Fe II component, and emission lines. In addition, it can run Monte Carlo iterations using flux randomization to estimate the uncertainties.
https://ui.adsabs.harvard.edu/abs/2018ascl.soft09008G , https://ui.adsabs.harvard.edu/abs/2019ApJS..241...34S