special: A Python package for the spectral characterization of directly imaged low-mass companions

SPECIAL is a Python package for the SPEctral Characterization of directly ImAged Low-mass companions. While some tools are specific to the characterisation of low-mass (M, L, T) dwarfs down to giant planets at optical/IR wavelengths, the main routines of SPECIAL (MCMC and nested samplers) can also be used in a more general way for the characterisation of any type of object with a measured spectrum, provided a relevant input model grid, regardless of the observational method used to obtain the spectrum (direct imaging or not) and regardless of the format of the spectra (multi-band photometry, low-resolution or medium-resolution spectrum, or a combination thereof).