old_contents: 
  import numpy as np
  from pytest import approx
  
  from fastats import windowed_pass
  
  
  def std(x):
      return np.std(x)
  
  
  def test_windowed_pass_basic_sanity():
      assert std([1, 2, 3]) == approx(0.816496580)
  
      data = np.array(range(100), dtype='float') ** 2
  
      res = windowed_pass(data, 5, value=std)
  
      assert np.isnan(res[0])
      assert np.isnan(res[1])
      assert np.isnan(res[2])
      assert np.isnan(res[3])
      assert res[4] == approx(5.89915248)
      assert res[5] == approx(8.64869932)
      assert res[-1] == approx(274.36253389)
  
  
  def mean(x):
      return np.sum(x) / x.size
  
  
  def test_windowed_pass_mean_size_5():
      assert mean(np.array([1, 2, 3])) == approx(2.0)
  
      data = np.array(range(100), dtype='float') ** 2
  
      res = windowed_pass(data, 5, value=mean)
  
      assert np.isnan(res[0])
      assert np.isnan(res[1])
      assert np.isnan(res[3])
      assert res[4] == approx(6.0)
      assert res[5] == approx(11.0)
      assert res[8] == approx(38.0)
      assert res[-1] == approx(9411.0)
  
  
  def test_windowed_pass_mean_size_10():
      data = np.array(range(100), dtype='float') ** 2
  
      res = windowed_pass(data, 10, value=mean)
  
      assert np.all(np.isnan(res[:9]))
      assert res[9] == approx(28.5)
      assert res[10] == approx(38.5)
      assert res[11] == approx(50.5)
      assert res[-1] == approx(8938.5)
  
  
  if __name__ == '__main__':
      import pytest
      pytest.main([__file__])
  
new_contents: 
  import numpy as np
  from pytest import approx
  
  from fastats import windowed_pass
  
  
  def std(x):
      return np.std(x)
  
  
  def test_windowed_pass_basic_sanity():
      assert std([1, 2, 3]) == approx(0.816496580)
  
      data = np.array(range(100), dtype='float') ** 2
  
      res = windowed_pass(data, 5, value=std)
  
      assert np.isnan(res[0])
      assert np.isnan(res[1])
      assert np.isnan(res[2])
      assert np.isnan(res[3])
      assert res[4] == approx(5.89915248)
      assert res[5] == approx(8.64869932)
      assert res[-1] == approx(274.36253389)
  
  
  def mean(x):
      return np.sum(x) / x.size
  
  
  def test_windowed_pass_mean_size_5():
      assert mean(np.array([1, 2, 3])) == approx(2.0)
  
      data = np.array(range(100), dtype='float') ** 2
  
      res = windowed_pass(data, 5, value=mean)
  
      assert np.isnan(res[0])
      assert np.isnan(res[1])
      assert np.isnan(res[3])
      assert res[4] == approx(6.0)
      assert res[5] == approx(11.0)
      assert res[8] == approx(38.0)
      assert res[-1] == approx(9411.0)
  
  
  def test_windowed_pass_mean_size_10():
      data = np.array(range(100), dtype='float') ** 2
  
      res = windowed_pass(data, 10, value=mean)
  
      assert np.all(np.isnan(res[:9]))
      assert res[9] == approx(28.5)
      assert res[10] == approx(38.5)
      assert res[11] == approx(50.5)
      assert res[-1] == approx(8938.5)
  
  
  def sum(x):
      return np.sum(x)
  
  
  def test_windowed_pass_sum():
      data = np.array(range(100), dtype='float')
  
      res = windowed_pass(data, 3, value=sum)
  
      assert np.isnan(res[0])
      assert np.isnan(res[1])
      assert res[2] == approx(3.0)
      assert res[3] == approx(6.0)
      assert res[4] == approx(9.0)
      assert res[-1] == approx(294.0)
  
      res5 = windowed_pass(data, 5, value=sum)
  
      assert np.all(np.isnan(res5[:4]))
      assert res5[5] == approx(15.0)
      assert res5[-1] == approx(485.0)
  
  
  if __name__ == '__main__':
      import pytest
      pytest.main([__file__])
  
subject: Add test