def parse_cols_arg(cols):
 if cols:
  if cols.endswith(','):
   cols += '0'
  col_list = [(int(x) - 1) for x in cols.split(',')]
  return col_list
 else:
  return BED_DEFAULT_COLS

def parse_cols_arg ( cols ) : if cols : if cols . endswith ( ',' ) : cols += '0' col_list = [ ( int ( x ) - 1 ) for x in cols . split ( ',' ) ] return col_list else : return BED_DEFAULT_COLS
parse a columns command line argument into a four-tuple .