code: def test_categorical_dtype(all_parsers, dtype):
      # see gh-10153
      parser = all_parsers
      data = """a,b,c
  1,a,3.4
  1,a,3.4
  2,b,4.5"""
      expected = DataFrame(
          {
              "a": Categorical(["1", "1", "2"]),
              "b": Categorical(["a", "a", "b"]),
              "c": Categorical(["3.4", "3.4", "4.5"]),
          }
      )
      actual = parser.read_csv(StringIO(data), dtype=dtype)
      tm.assert_frame_equal(actual, expected)
  
imports: from io import StringIO
  import os
  import numpy
  import pytest
  from pandas._libs import parsers
  from pandas.core.dtypes.dtypes import CategoricalDtype
  import pandas
  from pandas import Categorical, DataFrame, Timestamp
  import pandas._testing
label_desc: Use image node_id 1 for calling a global function with example usage: test_categorical_dtype(all_parsers, dtype) without return types