code: def units(self):
          
          
          return {'length':hash_to_unit(self.python_unit_l), 'mass':hash_to_unit(self.python_unit_m), 'time':hash_to_unit(self.python_unit_t)}
docs: Tuple of the units for length, time and mass.  Can be set in any order, and strings are not case-sensitive.  See ipython_examples/Units.ipynb for more information.  You can check the units' exact values and add Additional units in rebound/rebound/units.py.  Units should be set before adding particles to the simulation (will give error otherwise).
  
          Currently supported Units 
          -------------------------
  
          Times:
          Hr          : Hours
          Yr          : Julian years
          Jyr         : Julian years
          Sidereal_yr : Sidereal year
          Yr2pi       : Year divided by 2pi, with year defined as orbital period of planet at 1AU around 1Msun star
          Kyr         : Kiloyears (Julian)
          Myr         : Megayears (Julian)
          Gyr         : Gigayears (Julian)
  
          Lengths:
          M           : Meters
          Cm          : Centimeters
          Km          : Kilometers
          AU          : Astronomical Units
  
          Masses:
          Kg          : Kilograms
          Msun        : Solar masses
          Mmercury    : Mercury masses
          Mvenus      : Venus masses
          Mearth      : Earth masses
          Mmars       : Mars masses
          Mjupiter    : Jupiter masses
          Msaturn     : Saturn masses
          Muranus     : Neptune masses
          Mpluto      : Pluto masses
          
          Examples
          --------
          
          >>> sim = rebound.Simulation()
          >>> sim.units = ('yr', 'AU', 'Msun')