old_contents: import unittest
  import numpy as np
  
  from cxroots.IterativeMethods import newton
  from scipy import pi, cos, sin
  
  class TestNewton(unittest.TestCase):
  	def test_newton(self):
  		# result from keisan online calculator: http://keisan.casio.com/exec/system/1244946907
  		f  = lambda x: cos(x)-x
  		df = lambda x: -sin(x)-1
  
  		iterations = []
  		callback = lambda x, dx, y, iteration: iterations.append(x)
  		x, err = newton(pi/4, f, df, callback=callback)
  		iterations.append(x)
  		
  		correct_iterations = [0.73953613351523830094,
  							  0.7390851781060101829533,
  				  			  0.7390851332151610866198,
  				  			  0.7390851332151606416553]
  
  		np.testing.assert_almost_equal(iterations, correct_iterations, decimal=15)
  
  if __name__ == '__main__':
  	unittest.main()
  
new_contents: import pytest
  
  from cxroots.IterativeMethods import newton
  from scipy import pi, cos, sin
  
  def test_newton():
  	# result from keisan online calculator: http://keisan.casio.com/exec/system/1244946907
  	f  = lambda x: cos(x)-x
  	df = lambda x: -sin(x)-1
  
  	iterations = []
  	callback = lambda x, dx, y, iteration: iterations.append(x)
  	x, err = newton(pi/4, f, df, callback=callback)
  	iterations.append(x)
  	
  	correct_iterations = [0.73953613351523830094,
  						  0.7390851781060101829533,
  			  			  0.7390851332151610866198,
  			  			  0.7390851332151606416553]
  
  	assert iterations == pytest.approx(correct_iterations)
  
  
subject: Convert test_newton to pytest