  We describe a new open source package for calculating properties of galaxy
clusters, including NFW halo profiles with and without the effects of cluster
miscentering. This pure-Python package, cluster-lensing, provides
well-documented and easy-to-use classes and functions for calculating cluster
scaling relations, including mass-richness and mass-concentration relations
from the literature, as well as the surface mass density $\Sigma(R)$ and
differential surface mass density $\Delta\Sigma(R)$ profiles, probed by weak
lensing magnification and shear. Galaxy cluster miscentering is especially a
concern for stacked weak lensing shear studies of galaxy clusters, where
offsets between the assumed and the true underlying matter distribution can
lead to a significant bias in the mass estimates if not accounted for. This
software has been developed and released in a public GitHub repository, and is
licensed under the permissive MIT license. The cluster-lensing package is
archived on Zenodo (Ford 2016). Full documentation, source code, and
installation instructions are available at
http://jesford.github.io/cluster-lensing/.
