code: def purge_duplicates(list_in):
      
      _list = []
      for item in list_in:
          if item not in _list:
              _list.append(item)
      return _list
docs: Remove duplicates from list while preserving order.
  
      Parameters
      ----------
      list_in: Iterable
  
      Returns
      -------
      list
          List of first occurences in order