class_docstr: Groupby-specific tests.
class_docstr_tok: ["Groupby-specific","tests","."]
code: def test_grouping_grouper(self, data_for_grouping):
      df = pd.DataFrame(
          {
              "A": pd.Series(
                  ["B", "B", None, None, "A", "A", "B", "C"],
                  dtype=object,
              ),
              "B": data_for_grouping,
          }
      )
      gr1 = df.groupby("A")._grouper.groupings[0]
      gr2 = df.groupby("B")._grouper.groupings[0]
  
      tm.assert_numpy_array_equal(gr1.grouping_vector, df.A.values)
      tm.assert_extension_array_equal(
          gr2.grouping_vector, data_for_grouping
      )
  
file_path: pandas/pandas/tests/extension/base/groupby.py
imports: import re
  import pytest
  from pandas.core.dtypes.common import is_bool_dtype, is_numeric_dtype, is_object_dtype, is_string_dtype
  import pandas
  import pandas._testing
label_desc: Use image node_id 1 for calling the BaseGroupbyTests obj's underlying member method code with example usage: obj.test_grouping_grouper(data_for_grouping) without return types