How to use the eccodes.GribIndex function in eccodes

def test_create_and_serialize_index(self):
        """GribIndex can be saved to file, file can be added to index."""
        with GribIndex(TESTGRIB, TEST_KEYS) as idx:
            idx.write(TEST_INDEX)
        with GribIndex(file_index=TEST_INDEX) as idx:
            idx.add(TESTGRIB)
        os.unlink(TEST_INDEX)

def test_create_and_serialize_index(self):
        """GribIndex can be saved to file, file can be added to index."""
        with GribIndex(TESTGRIB, TEST_KEYS) as idx:
            idx.write(TEST_INDEX)
        with GribIndex(file_index=TEST_INDEX) as idx:
            idx.add(TESTGRIB)
        os.unlink(TEST_INDEX)

def test_create_and_serialize_index(self):
        """GribIndex can be saved to file, file can be added to index."""
        with GribIndex(TESTGRIB, TEST_KEYS) as idx:
            idx.write(TEST_INDEX)
        with GribIndex(file_index=TEST_INDEX) as idx:
            idx.add(TESTGRIB)
        os.unlink(TEST_INDEX)

def test_create_and_serialize_index(self):
        """GribIndex can be saved to file, file can be added to index."""
        with GribIndex(TESTGRIB, TEST_KEYS) as idx:
            idx.write(TEST_INDEX)
        with GribIndex(file_index=TEST_INDEX) as idx:
            idx.add(TESTGRIB)
        os.unlink(TEST_INDEX)

def test_memory_management(self):
        """GribIndex closes GribMessages properly."""
        with GribIndex(TESTGRIB, TEST_KEYS) as idx:
            idx.select(SELECTION_DICTIONARY)
            self.assertEqual(len(idx.open_messages), 1)
        self.assertEqual(len(idx.open_messages), 0)

def test_index_comprehension(self):
        """GribIndex understands underlying GRIB index properly."""
        with GribIndex(TESTGRIB, TEST_KEYS) as idx:
            self.assertEqual(idx.size(TEST_KEYS[1]), 5)
            self.assertSequenceEqual(idx.values(TEST_KEYS[1]), TEST_STEPRANGE)
            with self.assertRaises(IndexNotSelectedError):
                # Note: The following will issue a message to stderr:
                #   ECCODES ERROR   :  please select a value for index key "dataDate"
                # This is expected behaviour
                idx.select({TEST_KEYS[1]: TEST_VALUES[0]})
            # Now it will be OK as we have selected all necessary keys
            idx.select(SELECTION_DICTIONARY)
            self.assertEqual(len(idx.open_messages), 1)

def test_memory_management(self):
        """GribIndex closes GribMessages properly."""
        with GribIndex(TESTGRIB, TEST_KEYS) as idx:
            idx.select(SELECTION_DICTIONARY)
            self.assertEqual(len(idx.open_messages), 1)
        self.assertEqual(len(idx.open_messages), 0)

def test_index_comprehension(self):
        """GribIndex understands underlying GRIB index properly."""
        with GribIndex(TESTGRIB, TEST_KEYS) as idx:
            self.assertEqual(idx.size(TEST_KEYS[1]), 5)
            self.assertSequenceEqual(idx.values(TEST_KEYS[1]), TEST_STEPRANGE)
            with self.assertRaises(IndexNotSelectedError):
                # Note: The following will issue a message to stderr:
                #   ECCODES ERROR   :  please select a value for index key "dataDate"
                # This is expected behaviour
                idx.select({TEST_KEYS[1]: TEST_VALUES[0]})
            # Now it will be OK as we have selected all necessary keys
            idx.select(SELECTION_DICTIONARY)
            self.assertEqual(len(idx.open_messages), 1)