old_contents: """Reusable math functions for the molecular scientists."""
  
  
  def dilute_stock(cI, vI, **values):
      """Dilute a stock concentration."""
      if not values:
          raise UserWarning('You did not enter any values.')
      for key, value in values.items():
          if key == 'vF' or 'vf':
              value = values['vF']
              final_concentration = (cI*vI)/value
              return final_concentration
          elif key == 'cF' or 'cf':
              value = values['cF']
              final_volume = (cI*vI) / value
              return final_volume
          else:
              raise KeyError('%s is not a valid key.' % key)
  
new_contents: """Reusable math functions for the molecular scientists."""
  
  
  def dilute_stock(cI, vI, **values):
      """Dilute a stock concentration."""
      if not values:
          raise UserWarning('You did not enter any values.')
      for key, value in values.items():
          if key == 'vF' or 'vf':
              value = values['vF']
              final_concentration = (cI*vI)/value
              return final_concentration
          elif key == 'cF' or 'cf':
              value = values['cF']
              final_volume = (cI*vI) / value
              return final_volume
          else:
              raise KeyError('%s is not a valid key.' % key)
   
  def mass_recorder(grams, item, Sigfigs):
      "Record the mass of different items"
      item_Dict = {}
      if isinstance(grams, float) and isinstance(item, str) and isinstance(Sigfigs, int):
          if item in item_Dict:
              formatter = "{0:."+Str(Sigfigs)+"f}"
              grams = formatter.format(grams)
              item_Dict[item] = grams
          else:
              formatter = "{0:."+Str(Sigfigs)+"f}"
              grams = formatter.format(grams)
              item_Dict[item]+= grams
      else:
          raise UserWarning('Please print grams as a float value, item as a string, and sigfigs as an integer value")
  
subject: Update functions.py