code: def get_regular_master(font):
      
      if not font.masters:
          return None
      regular_name = font.customParameters["Variation Font Origin"]
      if regular_name is not None:
          for master in font.masters:
              if master.name == regular_name:
                  return master
      base_style = find_base_style(font.masters)
      if not base_style:
          base_style = "Regular"
      for master in font.masters:
          if master.name == base_style:
              return master
      # Second try: maybe the base style has regular in it as well
      for master in font.masters:
          name_without_regular = " ".join(
              n for n in master.name.split(" ") if n != "Regular"
          )
          if name_without_regular == base_style:
              return master
      return font.masters[0]
docs: Find the "regular" master among the GSFontMasters.
  
      Tries to find the master with the passed 'regularName'.
      If there is no such master or if regularName is None,
      tries to find a base style shared between all masters
      (defaulting to "Regular"), and then tries to find a master
      with that style name. If there is no master with that name,
      returns the first master in the list.