code: def test_strings_cat(df_strings):
      """Test output on categorical columns"""
      df_strings.columns = df_strings.columns.astype("category")
      assert_frame_equal(
          df_strings.select_columns("id"), df_strings.loc[:, ["id"]]
      )
      assert_frame_equal(
          df_strings.select_columns("*type*"),
          df_strings.filter(like="type"),
      )
  
imports: import datetime
  import re
  from itertools import product
  import numpy
  import pandas
  import pytest
  from pandas.api.types import is_numeric_dtype
  from pandas.testing import assert_frame_equal
  from janitor.functions.utils import DropLabel, get_columns, patterns
label_desc: Use image node_id 15 for calling a global function with example usage: test_strings_cat(df_strings) without return types