def dir_size(start_path):
 total_size = 0
 for (dirpath, dirnames, filenames) in os.walk(start_path):
  for f in filenames:
   fp = os.path.join(dirpath, f)
   if (not os.path.islink(fp)):
    total_size += os.path.getsize(fp)
 return total_size

def dir_size ( start_path ) : total_size = 0 for ( dirpath , dirnames , filenames ) in os . walk ( start_path ) : for f in filenames : fp = os . path . join ( dirpath , f ) if ( not os . path . islink ( fp ) ) : total_size += os . path . getsize ( fp ) return total_size
calculates the total size .