code: def test_dtype_per_column(all_parsers):
      parser = all_parsers
      data = """\
  one,two
  1,2.5
  2,3.5
  3,4.5
  4,5.5"""
      expected = DataFrame(
          [[1, "2.5"], [2, "3.5"], [3, "4.5"], [4, "5.5"]],
          columns=["one", "two"],
      )
      expected["one"] = expected["one"].astype(np.float64)
      expected["two"] = expected["two"].astype(object)
  
      result = parser.read_csv(
          StringIO(data), dtype={"one": np.float64, 1: str}
      )
      tm.assert_frame_equal(result, expected)
  
imports: from collections import defaultdict
  from io import StringIO
  import numpy
  import pytest
  from pandas.errors import ParserWarning
  import pandas
  from pandas import DataFrame, Timestamp
  import pandas._testing
  from pandas.core.arrays import ArrowStringArray, IntegerArray, StringArray
label_desc: Use image node_id 2 for calling a global function with example usage: test_dtype_per_column(all_parsers) without return types