old_contents: from skyfield.api import load
  from skyfield.magnitudelib import planetary_magnitude
  
  def test_magnitudes():
      ts = load.timescale()
      #t = ts.utc(1995, 5, 22)  # Rings edge-on from Earth.
      t = ts.utc(2021, 10, 4)
      eph = load('de421.bsp')
      names = [
          'mercury', 'venus', 'mars', 'jupiter barycenter',
          'saturn barycenter', 'uranus barycenter', 'neptune barycenter',
      ]
      e = eph['earth'].at(t)
      positions = [e.observe(eph[name]) for name in names]
      magnitudes = [planetary_magnitude(position) for position in positions]
      assert [f'{m:.3f}' for m in magnitudes] == [
          '2.393', '-4.278', '1.592', '-2.693', '0.508', '5.701', '7.690',
      ]
  
new_contents: from skyfield.api import load
  from skyfield.magnitudelib import planetary_magnitude
  
  def test_magnitudes():
      ts = load.timescale()
      #t = ts.utc(1995, 5, 22)  # Rings edge-on from Earth.
      t = ts.utc(2021, 10, 4)
      eph = load('de421.bsp')
      names = [
          'mercury', 'venus', 'mars', 'jupiter barycenter',
          'saturn barycenter', 'uranus barycenter', 'neptune barycenter',
      ]
      e = eph['earth'].at(t)
      positions = [e.observe(eph[name]) for name in names]
      magnitudes = [planetary_magnitude(position) for position in positions]
      assert ['%.3f' % m for m in magnitudes] == [
          '2.393', '-4.278', '1.592', '-2.693', '0.508', '5.701', '7.690',
      ]
  
subject: Fix magnitudes test for Python 2.7 in CI