code: def test_table_split_by_pandas_date_correct(self):
      data = {
          "a": [date(2020, i, 15) for i in range(1, 13)],
          "b": [i for i in range(1, 13)],
      }
      table = Table(pd.DataFrame(data))
      view = table.view(columns=["a", "b"], split_by=["a"])
      assert view.to_columns() == {
          "2020-01-15|a": [
              datetime(2020, 1, 15, 0, 0),
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-01-15|b": [
              1,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-02-15|a": [
              None,
              datetime(2020, 2, 15, 0, 0),
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-02-15|b": [
              None,
              2,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-03-15|a": [
              None,
              None,
              datetime(2020, 3, 15, 0, 0),
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-03-15|b": [
              None,
              None,
              3,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-04-15|a": [
              None,
              None,
              None,
              datetime(2020, 4, 15, 0, 0),
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-04-15|b": [
              None,
              None,
              None,
              4,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-05-15|a": [
              None,
              None,
              None,
              None,
              datetime(2020, 5, 15, 0, 0),
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-05-15|b": [
              None,
              None,
              None,
              None,
              5,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-06-15|a": [
              None,
              None,
              None,
              None,
              None,
              datetime(2020, 6, 15, 0, 0),
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-06-15|b": [
              None,
              None,
              None,
              None,
              None,
              6,
              None,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-07-15|a": [
              None,
              None,
              None,
              None,
              None,
              None,
              datetime(2020, 7, 15, 0, 0),
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-07-15|b": [
              None,
              None,
              None,
              None,
              None,
              None,
              7,
              None,
              None,
              None,
              None,
              None,
          ],
          "2020-08-15|a": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              datetime(2020, 8, 15, 0, 0),
              None,
              None,
              None,
              None,
          ],
          "2020-08-15|b": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              8,
              None,
              None,
              None,
              None,
          ],
          "2020-09-15|a": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              datetime(2020, 9, 15, 0, 0),
              None,
              None,
              None,
          ],
          "2020-09-15|b": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              9,
              None,
              None,
              None,
          ],
          "2020-10-15|a": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              datetime(2020, 10, 15, 0, 0),
              None,
              None,
          ],
          "2020-10-15|b": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              10,
              None,
              None,
          ],
          "2020-11-15|a": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              datetime(2020, 11, 15, 0, 0),
              None,
          ],
          "2020-11-15|b": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              11,
              None,
          ],
          "2020-12-15|a": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              datetime(2020, 12, 15, 0, 0),
          ],
          "2020-12-15|b": [
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              None,
              12,
          ],
      }
  
file_path: perspective/python/perspective/perspective/tests/table/test_table_datetime.py
imports: import os
  import time
  import pytz
  import numpy
  import pandas
  from datetime import date, datetime, timedelta
  from dateutil import tz
  from pytest import mark
  from perspective.table import Table
label_desc: Use image node_id 4 for calling the TestTableDateTimePivots obj's underlying member method code with example usage: obj.test_table_split_by_pandas_date_correct() without return types