def bandpass_pre_cache(lows=(80, 100, 120), highs=(1200, 3000, 8000), bands=((2000, 8000),), rate=44100):
 for low in lows:
  for high in highs:
   _butter(6, (low, high), rate=rate)
 for band in bands:
  _butter(6, band, rate=rate)

def bandpass_pre_cache ( lows = ( 80 , 100 , 120 ) , highs = ( 1200 , 3000 , 8000 ) , bands = ( ( 2000 , 8000 ) , ) , rate = 44100 ) : for low in lows : for high in highs : _butter ( 6 , ( low , high ) , rate = rate ) for band in bands : _butter ( 6 , band , rate = rate )
call _butter now to cache some useful values .