code: def test_from_object():
      df = conversion_data()
      data_id, column_type = "1", "type_conversion"
      i = 0
      build_data_inst({data_id: df})
  
      cfg = {
          "col": "str_date",
          "to": "date",
          "from": "object",
          "fmt": "%Y%m%d",
      }
      builder = ColumnBuilder(
          data_id, column_type, "Col{}".format(++i), cfg
      )
      verify_builder(
          builder,
          lambda col: pd.Timestamp(col.values[0]).strftime("%Y%m%d")
          == "20200101",
      )
  
      cfg = {"col": "str_date2", "to": "date", "from": "object"}
      builder = ColumnBuilder(
          data_id, column_type, "Col{}".format(++i), cfg
      )
      verify_builder(
          builder,
          lambda col: pd.Timestamp(col.values[0]).strftime("%Y%m%d")
          == "20200101",
      )
  
      cfg = {"col": "str_bool", "to": "bool", "from": "object"}
      builder = ColumnBuilder(
          data_id, column_type, "Col{}".format(++i), cfg
      )
      verify_builder(builder, lambda col: col.values[0])
  
file_path: dtale/tests/dtale/column_builders/test_type_conversion.py
imports: import numpy
  import pandas
  import pytest
  from dtale.column_builders import ColumnBuilder
  from tests.dtale.column_builders.test_column_builders import verify_builder
  from tests.dtale import build_data_inst
label_desc: Use image node_id 3 for calling a global function with example usage: test_from_object() without return types