class_docstr: Various Series and DataFrame methods.
class_docstr_tok: ["Various","Series","and","DataFrame","methods","."]
code: def test_factorize_empty(self, data):
      codes, uniques = pd.factorize(data[:0])
      expected_codes = np.array([], dtype=np.intp)
      expected_uniques = type(data)._from_sequence(
          [], dtype=data[:0].dtype
      )
  
      tm.assert_numpy_array_equal(codes, expected_codes)
      tm.assert_extension_array_equal(uniques, expected_uniques)
  
imports: import inspect
  import operator
  import numpy
  import pytest
  from pandas._typing import Dtype
  from pandas.core.dtypes.common import is_bool_dtype
  from pandas.core.dtypes.dtypes import NumpyEADtype
  from pandas.core.dtypes.missing import na_value_for_dtype
  import pandas
  import pandas._testing
  from pandas.core.sorting import nargsort
label_desc: Use image node_id 25 for calling the BaseMethodsTests obj's underlying member method code with example usage: obj.test_factorize_empty(data) without return types