import numpy
from matplotlib import pyplot

## Replace with your own samples and rate
samples = …
sampling_rate = 32e3

## Do a fourier transform of the whole data set
fourier_transform = numpy.fft.fft(samples)
positive_freq_components = fourier_transform[0:len(fourier_transform) / 2]
positive_freq_components_mag_squared = numpy.abs(positive_freq_components)**2
frequencies = numpy.linspace(0, sampling_rate / 2, len(fourier_transform) / 2)

## Plot that stuff!
pyplot.plot(frequencies, positive_freq_components_mag_squared)
pyplot.xlabel("Frequency (Hz)")
pyplot.ylabel("Digital Power")
pyplot.tight_layout()
pyplot.show()