sfsutils is a package for parsing site frequency spectra (SFS), with support for versatile stratification, ancestral allele and site-degeneracy annotation, and filtering. Beyond the one-dimensional spectrum it also derives the joint SFS across several populations and the two-site SFS of linked pairs of sites, and reads from VCF files, VCF-Zarr stores, and tskit tree sequences (ARGs).
Please see the documentation for all the details.