If you're looking for a Python RINEX OBS and NAV reader, check out Pynex.
Work in progress, fixing old Kai Borre Matlab code to run in Octave and hence be callable by Python to work with RINEX data
Working on updating the code to run in modern Matlab and Octave for use with oct2py in calling from Python.
Currently the functions easy3.m easy4.m easy5.m run in Octave and Matlab, reading the default included files.