code: def gff3_parse_attributes(attributes_string):
      
      
      attributes = dict()
      fields = attributes_string.split(';')
      for f in fields:
          if '=' in f:
              key, value = f.split('=')
              attributes[unquote_plus(key).strip()] = unquote_plus(value.strip())
          elif len(f) > 0:
              # not strictly kosher
              attributes[unquote_plus(f).strip()] = True            
      return attributes
docs: Parse a string of GFF3 attributes ('key=value' pairs delimited by ';') 
      and return a dictionary.