text: import numpy as np
  import pytest
  
  import pandas as pd
  from pandas import (
      DataFrame,
      Series,
      date_range,
  )
  import pandas._testing as tm
  
  
  class TestDataFrameUpdate:
      def test_update_nan(self):
          # #15593 #15617
          # test 1
          df1 = DataFrame({"A": [1.0, 2, 3], "B": date_range("2000", periods=3)})
          df2 = DataFrame({"A": [None, 2, 3]})
          expected = df1.copy()
          df1.update(df2, overwrite=False)
  
          tm.assert_frame_equal(df1, expected)
  
          # test 2
          df1 = DataFrame({"A": [1.0, None, 3], "B": date_range("2000", periods=3)})
          df2 = DataFrame({"A": [None, 2, 3]})
          expected = DataFrame({"A": [1.0, 2, 3], "B": date_range("2000", periods=3)})
          df1.update(df2, overwrite=False)
  
          tm.assert_frame_equal(df1, expected)
  
      def test_update(self):
          df = DataFrame(
              [[1.5, np.nan, 3.0], [1.5, np.nan, 3.0], [1.5, np.nan, 3], [1.5, np.nan, 3]]
          )
  
          other = DataFrame([[3.6, 2.0, np.nan], [np.nan, np.nan, 7]], index=[1, 3])
  
          df.update(other)
  
          expected = DataFrame(
              [[1.5, np.nan, 3], [3.6, 2, 3], [1.5, np.nan, 3], [1.5, np.nan, 7.0]]
          )
          tm.assert_frame_equal(df, expected)
  
      def test_update_dtypes(self):
  
          # gh 3016
          df = DataFrame(
              [[1.0, 2.0, False, True], [4.0, 5.0, True, False]],
              columns=["A", "B", "bool1", "bool2"],
          )
  
          other = DataFrame([[45, 45]], index=[0], columns=["A", "B"])
          df.update(other)
  
          expected = DataFrame(
              [[45.0, 45.0, False, True], [4.0, 5.0, True, False]],
              columns=["A", "B", "bool1", "bool2"],
          )
          tm.assert_frame_equal(df, expected)
  
      def test_update_nooverwrite(self):
          df = DataFrame(
              [[1.5, np.nan, 3.0], [1.5, np.nan, 3.0], [1.5, np.nan, 3], [1.5, np.nan, 3]]
          )
  
          other = DataFrame([[3.6, 2.0, np.nan], [np.nan, np.nan, 7]], index=[1, 3])
  
          df.update(other, overwrite=False)
  
          expected = DataFrame(
              [[1.5, np.nan, 3], [1.5, 2, 3], [1.5, np.nan, 3], [1.5, np.nan, 3.0]]
          )
          tm.assert_frame_equal(df, expected)
  
      def test_update_filtered(self):
          df = DataFrame(
              [[1.5, np.nan, 3.0], [1.5, np.nan, 3.0], [1.5, np.nan, 3], [1.5, np.nan, 3]]
          )
  
          other = DataFrame([[3.6, 2.0, np.nan], [np.nan, np.nan, 7]], index=[1, 3])
  
          df.update(other, filter_func=lambda x: x > 2)
  
          expected = DataFrame(
              [[1.5, np.nan, 3], [1.5, np.nan, 3], [1.5, np.nan, 3], [1.5, np.nan, 7.0]]
          )
          tm.assert_frame_equal(df, expected)
  
      @pytest.mark.parametrize(
          "bad_kwarg, exception, msg",
          [
              # errors must be 'ignore' or 'raise'
              ({"errors": "something"}, ValueError, "The parameter errors must.*"),
              ({"join": "inner"}, NotImplementedError, "Only left join is supported"),
          ],
      )
      def test_update_raise_bad_parameter(self, bad_kwarg, exception, msg):
          df = DataFrame([[1.5, 1, 3.0]])
          with pytest.raises(exception, match=msg):
              df.update(df, **bad_kwarg)
  
      def test_update_raise_on_overlap(self):
          df = DataFrame(
              [[1.5, 1, 3.0], [1.5, np.nan, 3.0], [1.5, np.nan, 3], [1.5, np.nan, 3]]
          )
  
          other = DataFrame([[2.0, np.nan], [np.nan, 7]], index=[1, 3], columns=[1, 2])
          with pytest.raises(ValueError, match="Data overlaps"):
              df.update(other, errors="raise")
  
      def test_update_from_non_df(self):
          d = {"a": Series([1, 2, 3, 4]), "b": Series([5, 6, 7, 8])}
          df = DataFrame(d)
  
          d["a"] = Series([5, 6, 7, 8])
          df.update(d)
  
          expected = DataFrame(d)
  
          tm.assert_frame_equal(df, expected)
  
          d = {"a": [1, 2, 3, 4], "b": [5, 6, 7, 8]}
          df = DataFrame(d)
  
          d["a"] = [5, 6, 7, 8]
          df.update(d)
  
          expected = DataFrame(d)
  
          tm.assert_frame_equal(df, expected)
  
      def test_update_datetime_tz(self):
          # GH 25807
          result = DataFrame([pd.Timestamp("2019", tz="UTC")])
          result.update(result)
          expected = DataFrame([pd.Timestamp("2019", tz="UTC")])
          tm.assert_frame_equal(result, expected)
  
      def test_update_with_different_dtype(self):
          # GH#3217
          df = DataFrame({"a": [1, 3], "b": [np.nan, 2]})
          df["c"] = np.nan
          df["c"].update(Series(["foo"], index=[0]))
  
          expected = DataFrame({"a": [1, 3], "b": [np.nan, 2], "c": ["foo", np.nan]})
          tm.assert_frame_equal(df, expected)
  