For example, if I ran the module to get the star formation rates like this:
sfr = StarFormationRate(pf, data_source=all)
How can I access the contents of sfr in the script itself, rather than just writing it out to a file?
You should look at the write_out() function in the source:
in the for loop for inspiration. In the source things that are named 'self.mass_bins', for example, can be accessed as 'sfr.mass_bins' if you do things as you've said above.