old_contents: from galpy.util import config
  _APY_LOADED= True
  try:
      from astropy import units
  except ImportError:
      _APY_LOADED= False
  class df(object):
      """Top-level class for DF classes"""
      def __init__(self,ro=None,vo=None):
          """
          NAME:
             __init__
          PURPOSE:
             initialize a DF object
          INPUT:
             ro= (None) distance scale
             vo= (None) velocity scale
          OUTPUT:
          HISTORY:
             2016-02-28 - Written - Bovy (UofT)
          """
          # Parse ro and vo
          if ro is None:
              self._ro= config.__config__.getfloat('normalization','ro')
              self._roSet= False
          else:
              if _APY_LOADED and isinstance(ro,units.Quantity):
                  ro= ro.to(units.kpc).value
              self._ro= ro
              self._roSet= True
          if vo is None:
              self._vo= config.__config__.getfloat('normalization','vo')
              self._voSet= False
          else:
              if _APY_LOADED and isinstance(vo,units.Quantity):
                  vo= vo.to(units.km/units.s).value
              self._vo= vo
              self._voSet= True
          return None
  
new_contents: from galpy.util import config
  _APY_LOADED= True
  try:
      from astropy import units
  except ImportError:
      _APY_LOADED= False
  class df(object):
      """Top-level class for DF classes"""
      def __init__(self,ro=None,vo=None):
          """
          NAME:
             __init__
          PURPOSE:
             initialize a DF object
          INPUT:
             ro= (None) distance scale
             vo= (None) velocity scale
          OUTPUT:
          HISTORY:
             2016-02-28 - Written - Bovy (UofT)
          """
          # Parse ro and vo
          if ro is None:
              self._ro= config.__config__.getfloat('normalization','ro')
              self._roSet= False
          else:
              if _APY_LOADED and isinstance(ro,units.Quantity):
                  ro= ro.to(units.kpc).value
              self._ro= ro
              self._roSet= True
          if vo is None:
              self._vo= config.__config__.getfloat('normalization','vo')
              self._voSet= False
          else:
              if _APY_LOADED and isinstance(vo,units.Quantity):
                  vo= vo.to(units.km/units.s).value
              self._vo= vo
              self._voSet= True
          return None
  
      def turn_physical_off(self):
          """
          NAME:
  
             turn_physical_off
  
          PURPOSE:
  
             turn off automatic returning of outputs in physical units
  
          INPUT:
  
             (none)
  
          OUTPUT:
  
             (none)
  
          HISTORY:
  
             2017-06-05 - Written - Bovy (UofT)
  
          """
          self._roSet= False
          self._voSet= False
          return None
  
      def turn_physical_on(self,ro=None,vo=None):
          """
          NAME:
  
             turn_physical_on
  
          PURPOSE:
  
             turn on automatic returning of outputs in physical units
  
          INPUT:
  
             ro= reference distance (kpc; can be Quantity)
  
             vo= reference velocity (km/s; can be Quantity)
  
          OUTPUT:
  
             (none)
  
          HISTORY:
  
             2016-06-05 - Written - Bovy (UofT)
  
          """
          self._roSet= True
          self._voSet= True
          if not ro is None:
              if _APY_LOADED and isinstance(ro,units.Quantity):
                  ro= ro.to(units.kpc).value
              self._ro= ro
          if not vo is None:
              if _APY_LOADED and isinstance(vo,units.Quantity):
                  vo= vo.to(units.km/units.s).value
              self._vo= vo
          return None  
  
subject: Allow df methods' physical output to be turned off