old_contents: 
  import numpy as np
  from numpy import power, mean
  
  
  def sum_sq_dev(x):
      """
      Sum of squared deviations.
  
      :param x: Numpy array
      :return: Scalar of type `x.dtype`
  
      >>> x = np.array([205.,195.,210.,340.,299.,
      ...               230.,270.,243.,340.,240.])
      >>> sum_sq_dev(x) # doctest: +ELLIPSIS
      25681.60000...
      """
      population_mean = mean(x)
      total = 0.0
  
      for value in x:
          total += power((value - population_mean), 2)
  
      return total
  
  
  if __name__ == '__main__':
      import pytest
      pytest.main([__file__])
  
new_contents: 
  from numpy import power, mean
  
  
  def sum_sq_dev(x):
      """
      Sum of squared deviations.
  
      :param x: Numpy array
      :return: Scalar of type `x.dtype`
  
      >>> import numpy as np
      >>> x = np.array([205.,195.,210.,340.,299.,
      ...               230.,270.,243.,340.,240.])
      >>> sum_sq_dev(x) # doctest: +ELLIPSIS
      25681.60000...
      """
      population_mean = mean(x)
      total = 0.0
  
      for value in x:
          total += power((value - population_mean), 2)
  
      return total
  
  
  if __name__ == '__main__':
      import pytest
      pytest.main([__file__])
  
subject: Remove doctest specific import