old_contents: import pyradex
  import pyradex.fjdu
  import pytest
  import os
  import distutils.spawn
  import numpy as np
  from astropy import units as u
  
  def data_path(filename):
      data_dir = os.path.join(os.path.dirname(__file__), 'data')
      return os.path.join(data_dir, filename)
  
  def test_thin_co():
      density = {'oH2': 100,
                 'pH2': 900,
                }
      RR = pyradex.Radex(species='co', column=1e10, density=density, temperature=20)
      FF = pyradex.fjdu.Fjdu(species='co', column=1e10, density=density, temperature=20)
  
      rtbl = RR()
      ftbl = FF()
  
      diff = rtbl['upperlevelpop'] - ftbl['upperlevelpop']
      #np.testing.assert_allclose(diff, 0)
  
new_contents: import pyradex
  import pyradex.fjdu
  import pytest
  import os
  import distutils.spawn
  import numpy as np
  from astropy import units as u
  
  def data_path(filename):
      data_dir = os.path.join(os.path.dirname(__file__), 'data')
      return os.path.join(data_dir, filename)
  
  def test_thin_co():
      density = {'oH2': 100,
                 'pH2': 900,
                }
      RR = pyradex.Radex(datapath='examples/', species='co', column=1e10, density=density, temperature=20)
      FF = pyradex.fjdu.Fjdu(datapath='examples/', species='co', column=1e10, density=density, temperature=20)
  
      rtbl = RR()
      ftbl = FF()
  
      diff = rtbl['upperlevelpop'] - ftbl['upperlevelpop']
      #np.testing.assert_allclose(diff, 0)
  
  def test_thick_co():
      density = {'oH2': 100,
                 'pH2': 900,
                }
      RR = pyradex.Radex(datapath='examples/', species='co', column=1e17, density=density, temperature=20)
      FF = pyradex.fjdu.Fjdu(datapath='examples/', species='co', column=1e17, density=density, temperature=20)
  
      rtbl = RR()
      ftbl = FF()
  
      diff = rtbl['upperlevelpop'] - ftbl['upperlevelpop']
      #np.testing.assert_allclose(diff, 0)
  
subject: add datapath in tests