code: def test_regex_presence(df_dates):
      """
      Raise KeyError if search_value is a regex
      and the columns is not a string column.
      """
      with pytest.raises(KeyError, match=r"No match was returned.+"):
          df_dates.select_columns(re.compile(r"^\d+"))
  
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 20 for calling a global function with example usage: test_regex_presence(df_dates) without return types