text: import os
  import unittest
  
  import pymatgen
  from pymatgen.apps.battery.analyzer import BatteryAnalyzer
  from pymatgen.core.structure import Structure
  from pymatgen.util.testing import PymatgenTest
  
  
  class BatteryAnalyzerTest(PymatgenTest):
      def load_from_cif(self, filename, oxidations, cation="Li"):
          s = Structure.from_file(os.path.join(PymatgenTest.TEST_FILES_DIR, filename))
          s.add_oxidation_state_by_element(oxidations)
          return BatteryAnalyzer(s, cation)
  
      def load_from_internal(self, name, oxidations, cation="Li"):
          s = self.get_structure(name).copy()
          s.add_oxidation_state_by_element(oxidations)
          return BatteryAnalyzer(s, cation)
  
      def setUp(self):
          self.lifepo4 = self.load_from_internal("LiFePO4", {"Li": 1, "Fe": 2, "P": 5, "O": -2})
          self.nafepo4 = self.load_from_internal("NaFePO4", {"Na": 1, "Fe": 2, "P": 5, "O": -2}, cation="Na")
          self.fepo4 = self.load_from_cif("FePO4a.cif", {"Fe": 3, "P": 5, "O": -2})
          self.lifemnpo4 = self.load_from_cif("Li4Fe3Mn1(PO4)4.cif", {"Li": 1, "Fe": 2, "Mn": 2, "P": 5, "O": -2})
          self.li8nicofe208 = self.load_from_cif(
              "Li8Fe2NiCoO8.cif", {"Li": 1, "Fe": 2, "Mn": 2, "Co": 2, "Ni": 2, "O": -2}
          )
          self.li3v2p3o12 = self.load_from_internal("Li3V2(PO4)3", {"Li": 1, "V": 3, "O": -2, "P": 5})
  
      def test_oxid_check(self):
          s = self.get_structure("LiFePO4")
          self.assertRaises(ValueError, BatteryAnalyzer, s, "Li")
  
      def test_capacitygrav_calculations(self):
          lifepo4_cap = 169.89053  # same as fepo4 cap
          nafepo4_cap = 154.20331
          li3v2p3o12_cap_remove = 197.25339
          li3v2p3o12_cap_insert = 127.17129
  
          self.assertAlmostEqual(self.lifepo4.get_max_capgrav(), lifepo4_cap, 3)
          self.assertEqual(self.lifepo4.get_max_capgrav(remove=False), 0)
          self.assertAlmostEqual(self.lifepo4.get_max_capgrav(insert=False), lifepo4_cap, 3)
  
          self.assertAlmostEqual(self.nafepo4.get_max_capgrav(), nafepo4_cap, 3)
          self.assertEqual(self.nafepo4.get_max_capgrav(remove=False), 0)
  
          self.assertAlmostEqual(self.fepo4.get_max_capgrav(), lifepo4_cap, 3)
          self.assertEqual(self.fepo4.get_max_capgrav(insert=False), 0)
  
          self.assertAlmostEqual(self.li3v2p3o12.get_max_capgrav(insert=False), li3v2p3o12_cap_remove, 3)
          self.assertAlmostEqual(self.li3v2p3o12.get_max_capgrav(remove=False), li3v2p3o12_cap_insert, 3)
  
      def test_capacityvol_calculations(self):
          lifepo4_cap = 594.17518
          nafepo4_cap = 542.86104
          fepo4_cap = 624.82289  # this is different than lifepo4 cap if lifepo4 volume not known
  
          self.assertAlmostEqual(self.lifepo4.get_max_capvol(), lifepo4_cap, 3)
          self.assertEqual(self.lifepo4.get_max_capvol(remove=False), 0)
          self.assertAlmostEqual(self.lifepo4.get_max_capvol(insert=False), lifepo4_cap, 3)
  
          self.assertAlmostEqual(self.nafepo4.get_max_capvol(), nafepo4_cap, 3)
          self.assertEqual(self.nafepo4.get_max_capvol(remove=False), 0)
          self.assertAlmostEqual(self.nafepo4.get_max_capvol(insert=False), nafepo4_cap, 3)
  
          self.assertAlmostEqual(self.fepo4.get_max_capvol(), fepo4_cap, 3)
          self.assertAlmostEqual(self.fepo4.get_max_capvol(remove=False), fepo4_cap, 3)
          self.assertEqual(self.fepo4.get_max_capvol(insert=False), 0)
  
          # give the lifepo4 volume, should get lifepo4 capacity
          self.assertAlmostEqual(
              self.fepo4.get_max_capvol(volume=self.lifepo4.struc_oxid.volume),
              lifepo4_cap,
              3,
          )
  
      def test_delithiation(self):
          self.assertEqual(self.lifemnpo4.get_removals_int_oxid(), set([1.0, 2.0, 3.0, 4.0]))
  
          self.assertEqual(
              self.li8nicofe208.get_removals_int_oxid(),
              set([1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0]),
          )
  
          self.assertEqual(self.li3v2p3o12.get_removals_int_oxid(), set([4.0, 6.0]))
  
  
  if __name__ == "__main__":
      unittest.main()
  