old_contents: from __future__ import division
  import numpy as np
  import matplotlib.pyplot as plt
  
  
  def deconv(x, y, fs):
      X = np.fft.fft(x)
      Y = np.fft.fft(y)
      H = Y / X
      h = np.fft.ifft(H)
      print("h =", h)  # complex vector?
      t = np.arange(len(x)) / fs
      plt.plot(t, h.real)
      plt.grid()
      plt.title("impulse response")
      plt.show()
  
new_contents: """Response calculation."""
  from __future__ import division
  import numpy as np
  
  
  def calculate(signal_excitation, signal_out):
      """Function returns impulse response."""
      X = np.fft.fft(signal_excitation)
      Y = np.fft.fft(signal_out)
      H = Y / X
      h = np.fft.ifft(H)
      return h
  
subject: Change function content and pep257