wav_fft.py

from numpy import argmax
from scipy import arange
from scipy.io import wavfile
from scipy.fftpack import fftfreq, rfft, fftshift
import pylab

sample_rate, signal =  wavfile.read("goodnight.wav")


N = len(signal)
Fs = sample_rate
Ts = 1./Fs
freq_step = Fs/N
Y = fftshift(rfft(signal))
freq = freq_step * arange(-N/2,N/2)

pylab.plot(freq, abs(Y))
pylab.show()
print Y