라즈베리파이 파이썬2 FFT연산 도와 주세요ㅠㅠ

# Read in a WAV and find the freq's
#import pyaudio
import wave
import numpy as np
 
chunk = 2048
 
# open up a wave
wf = wave.open('/home/pi/Desktop/piproject/Korg-Trition-Slow-Choir-ST-C4.wav', 'rb')
swidth = wf.getsampwidth()
RATE = wf.getframerate()
# use a Blackman window
window = np.blackman(chunk)
# open stream
#p = pyaudio.PyAudio()
#stream = p.open(format =
#                p.get_format_from_width(wf.getsampwidth()),
#                channels = wf.getnchannels(),
#                rate = RATE,
#                output = True)
# read some data
data = wf.readframes(chunk)
# play stream and find the frequency of each chunk
while len(data) == chunk*swidth:
    # write data out to the audio stream
    # stream.write(data)
    # unpack the data and times by the hamming window
    indata = np.array(wave.struct.unpack("%dh"%(len(data)/swidth),\
                                         data))*window
    # Take the fft and square each value
    fftData=abs(np.fft.rfft(indata))**2
    # find the maximum
    which = fftData[1:].argmax() + 1
    # use quadratic interpolation around the max
    if which != len(fftData)-1:
        y0,y1,y2 = np.log(fftData[which-1:which+2:])
        x1 = (y2 - y0) * .5 / (2 * y1 - y2 - y0)
        # find the frequency and output it
        thefreq = (which+x1)*RATE/chunk
        print "The freq is %f Hz." % (thefreq)
    else:
        thefreq = which*RATE/chunk
        print "The freq is %f Hz." % (thefreq)
    # read some more data
    data = wf.readframes(chunk)
#if data:
#    stream.write(data)
#stream.close()
#p.terminate()