  Wavelength calibration is a routine and critical part of any spectral
work-flow, but many astronomers still resort to matching detected peaks and
emission lines by hand. We present RASCAL (RANSAC Assisted Spectral
CALibration), a python library for automated wavelength calibration of
astronomical spectrographs. RASCAL implements recent state-of-the-art methods
for wavelength calibration and requires minimal input from a user. In this
paper we discuss the implementation of the library and apply it to real-world
calibration spectra.
