Py6S is a Python interface to the respected 6S atmospheric Radiative Transfer Model which makes it significantly easier to use and adds useful new functionality. All of the functionality of the 6S model is supported, and various helper methods are provided to make common operations - such as running a simulation for a number of angles, or for all of the bands of a satellite sensor - very easy. Field spectroscopy data can also be imported and used to configure the ground reflectance of the model, allowing simulations of the at-sensor radiance that would be measured for a set of field spectral measurements. Py6S is fully integrated with the Python NumPy, pandas and Matplotlib modules to allow easy plotting of results and import/export of data. The code for Py6S can be accessed here.
PyProSAIL is a very simple Python interface to the ProSAIL combined leaf and canopy reflectance model. In a similar manner to Py6S, it provides a far nicer interface to the model, and allows easy plotting of the results. PyProSAIL can also be integrated very easily with Py6S, for example, to simulate how changes in leaf properties, and thus the reflectance of the canopy, would be manifested in the radiance received at a satellite. The code for PyProSAIL can be accessed here.
PySpectra is a python tool developed by the PML Remote Sensing Group and is available on GitHub. It assists in the importation of Spectra in various formats, including Ocean Optics and SVC 1024i formats as well as handling ASCII files, you can also import data formatted for ENVI or USGS. See the GitHub for more information.