From 9262c70fad9e0e1d28c8a080e85bb91d703f885a Mon Sep 17 00:00:00 2001
From: Raisa Dzhamtyrova <raya@MacBook-Pro.home>
Date: Mon, 10 Feb 2020 16:09:05 +0000
Subject: [PATCH 1/9] add messages to tests

---
 .../tests/extension/decimal/test_decimal.py   |  5 +-
 pandas/tests/extension/json/test_json.py      |  5 +-
 pandas/tests/extension/test_boolean.py        |  5 +-
 pandas/tests/extension/test_categorical.py    |  3 +-
 .../tests/frame/indexing/test_categorical.py  | 46 ++++++++++---------
 pandas/tests/frame/indexing/test_indexing.py  | 18 +++++---
 pandas/tests/frame/indexing/test_where.py     | 12 +++--
 pandas/tests/frame/methods/test_diff.py       |  2 +-
 pandas/tests/frame/methods/test_explode.py    |  5 +-
 pandas/tests/frame/methods/test_isin.py       | 13 ++++--
 pandas/tests/frame/methods/test_quantile.py   |  3 +-
 pandas/tests/frame/methods/test_replace.py    |  4 +-
 pandas/tests/frame/methods/test_round.py      | 23 ++++++----
 .../tests/frame/methods/test_sort_values.py   |  2 +-
 pandas/tests/frame/methods/test_to_dict.py    |  6 ++-
 15 files changed, 92 insertions(+), 60 deletions(-)

diff --git a/pandas/tests/extension/decimal/test_decimal.py b/pandas/tests/extension/decimal/test_decimal.py
index a78e4bb34e42a..fa69f025bd0fd 100644
--- a/pandas/tests/extension/decimal/test_decimal.py
+++ b/pandas/tests/extension/decimal/test_decimal.py
@@ -146,9 +146,10 @@ class TestMissing(BaseDecimal, base.BaseMissingTests):
 
 class Reduce:
     def check_reduce(self, s, op_name, skipna):
-
         if op_name in ["median", "skew", "kurt"]:
-            with pytest.raises(NotImplementedError):
+            # breakpoint()
+            msg = r"decimal does not support the .* operation"
+            with pytest.raises(NotImplementedError, match=msg):
                 getattr(s, op_name)(skipna=skipna)
 
         else:
diff --git a/pandas/tests/extension/json/test_json.py b/pandas/tests/extension/json/test_json.py
index f7ca99be2adea..6a85c4efe29d4 100644
--- a/pandas/tests/extension/json/test_json.py
+++ b/pandas/tests/extension/json/test_json.py
@@ -136,10 +136,11 @@ def test_custom_asserts(self):
         self.assert_frame_equal(a.to_frame(), a.to_frame())
 
         b = pd.Series(data.take([0, 0, 1]))
-        with pytest.raises(AssertionError):
+        msg = r"ExtensionArray are different.*"
+        with pytest.raises(AssertionError, match=msg):
             self.assert_series_equal(a, b)
 
-        with pytest.raises(AssertionError):
+        with pytest.raises(AssertionError, match=msg):
             self.assert_frame_equal(a.to_frame(), b.to_frame())
 
 
diff --git a/pandas/tests/extension/test_boolean.py b/pandas/tests/extension/test_boolean.py
index 0c6b187eac1fc..26795b9d23eff 100644
--- a/pandas/tests/extension/test_boolean.py
+++ b/pandas/tests/extension/test_boolean.py
@@ -112,7 +112,8 @@ def _check_op(self, s, op, other, op_name, exc=NotImplementedError):
                 # subtraction for bools raises TypeError (but not yet in 1.13)
                 if _np_version_under1p14:
                     pytest.skip("__sub__ does not yet raise in numpy 1.13")
-                with pytest.raises(TypeError):
+                msg = r"numpy boolean subtract, the \`-\` operator, is not supported.*"
+                with pytest.raises(TypeError, match=msg):
                     op(s, other)
 
                 return
@@ -139,7 +140,7 @@ def _check_op(self, s, op, other, op_name, exc=NotImplementedError):
                 expected[result.isna()] = np.nan
             self.assert_series_equal(result, expected)
         else:
-            with pytest.raises(exc):
+            with pytest.raises(exc, match=msg):
                 op(s, other)
 
     def _check_divmod_op(self, s, op, other, exc=None):
diff --git a/pandas/tests/extension/test_categorical.py b/pandas/tests/extension/test_categorical.py
index 336b23e54d74c..69a97f5c9fe02 100644
--- a/pandas/tests/extension/test_categorical.py
+++ b/pandas/tests/extension/test_categorical.py
@@ -278,7 +278,8 @@ def _compare_other(self, s, data, op_name, other):
             assert (result == expected).all()
 
         else:
-            with pytest.raises(TypeError):
+            msg = "Unordered Categoricals can only compare equality or not"
+            with pytest.raises(TypeError, match=msg):
                 op(data, other)
 
 
diff --git a/pandas/tests/frame/indexing/test_categorical.py b/pandas/tests/frame/indexing/test_categorical.py
index 3a472a8b58b6c..e2a7b11eb7a13 100644
--- a/pandas/tests/frame/indexing/test_categorical.py
+++ b/pandas/tests/frame/indexing/test_categorical.py
@@ -115,7 +115,11 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        with pytest.raises(ValueError):
+        msg = (
+            r"(:?Cannot setitem on a Categorical with a new category.*)"
+            r"|(:?Cannot set a Categorical with another, without identical categories)"
+        )
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.iloc[2, 0] = "c"
 
@@ -125,7 +129,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_row)
 
         #   - assign a complete row (mixed values) not in categories set
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.iloc[2, :] = ["c", 2]
 
@@ -134,7 +138,7 @@ def test_assigning_ops(self):
         df.iloc[2:4, :] = [["b", 2], ["b", 2]]
         tm.assert_frame_equal(df, exp_multi_row)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.iloc[2:4, :] = [["c", 2], ["c", 2]]
 
@@ -144,12 +148,12 @@ def test_assigning_ops(self):
         df.iloc[2:4, 0] = Categorical(["b", "b"], categories=["a", "b"])
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             # different categories -> not sure if this should fail or pass
             df = orig.copy()
             df.iloc[2:4, 0] = Categorical(list("bb"), categories=list("abc"))
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             # different values
             df = orig.copy()
             df.iloc[2:4, 0] = Categorical(list("cc"), categories=list("abc"))
@@ -160,7 +164,7 @@ def test_assigning_ops(self):
         df.iloc[2:4, 0] = ["b", "b"]
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df.iloc[2:4, 0] = ["c", "c"]
 
         #  loc
@@ -175,7 +179,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.loc["j", "cats"] = "c"
 
@@ -185,7 +189,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_row)
 
         #   - assign a complete row (mixed values) not in categories set
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.loc["j", :] = ["c", 2]
 
@@ -194,7 +198,7 @@ def test_assigning_ops(self):
         df.loc["j":"k", :] = [["b", 2], ["b", 2]]
         tm.assert_frame_equal(df, exp_multi_row)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.loc["j":"k", :] = [["c", 2], ["c", 2]]
 
@@ -204,14 +208,14 @@ def test_assigning_ops(self):
         df.loc["j":"k", "cats"] = Categorical(["b", "b"], categories=["a", "b"])
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             # different categories -> not sure if this should fail or pass
             df = orig.copy()
             df.loc["j":"k", "cats"] = Categorical(
                 ["b", "b"], categories=["a", "b", "c"]
             )
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             # different values
             df = orig.copy()
             df.loc["j":"k", "cats"] = Categorical(
@@ -224,7 +228,7 @@ def test_assigning_ops(self):
         df.loc["j":"k", "cats"] = ["b", "b"]
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df.loc["j":"k", "cats"] = ["c", "c"]
 
         #  loc
@@ -239,7 +243,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.loc["j", df.columns[0]] = "c"
 
@@ -249,7 +253,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_row)
 
         #   - assign a complete row (mixed values) not in categories set
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.loc["j", :] = ["c", 2]
 
@@ -258,7 +262,7 @@ def test_assigning_ops(self):
         df.loc["j":"k", :] = [["b", 2], ["b", 2]]
         tm.assert_frame_equal(df, exp_multi_row)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.loc["j":"k", :] = [["c", 2], ["c", 2]]
 
@@ -268,14 +272,14 @@ def test_assigning_ops(self):
         df.loc["j":"k", df.columns[0]] = Categorical(["b", "b"], categories=["a", "b"])
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             # different categories -> not sure if this should fail or pass
             df = orig.copy()
             df.loc["j":"k", df.columns[0]] = Categorical(
                 ["b", "b"], categories=["a", "b", "c"]
             )
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             # different values
             df = orig.copy()
             df.loc["j":"k", df.columns[0]] = Categorical(
@@ -288,7 +292,7 @@ def test_assigning_ops(self):
         df.loc["j":"k", df.columns[0]] = ["b", "b"]
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df.loc["j":"k", df.columns[0]] = ["c", "c"]
 
         # iat
@@ -297,7 +301,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.iat[2, 0] = "c"
 
@@ -308,7 +312,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.at["j", "cats"] = "c"
 
@@ -332,7 +336,7 @@ def test_assigning_ops(self):
         df.at["j", "cats"] = "b"
         tm.assert_frame_equal(df, exp_single_cats_value)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df = orig.copy()
             df.at["j", "cats"] = "c"
 
diff --git a/pandas/tests/frame/indexing/test_indexing.py b/pandas/tests/frame/indexing/test_indexing.py
index d892e3d637772..6d7f1e465dfa3 100644
--- a/pandas/tests/frame/indexing/test_indexing.py
+++ b/pandas/tests/frame/indexing/test_indexing.py
@@ -481,7 +481,8 @@ def test_setitem(self, float_frame):
         # so raise/warn
         smaller = float_frame[:2]
 
-        with pytest.raises(com.SettingWithCopyError):
+        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame.*"
+        with pytest.raises(com.SettingWithCopyError, match=msg):
             smaller["col10"] = ["1", "2"]
 
         assert smaller["col10"].dtype == np.object_
@@ -865,7 +866,8 @@ def test_fancy_getitem_slice_mixed(self, float_frame, float_string_frame):
         # setting it triggers setting with copy
         sliced = float_frame.iloc[:, -3:]
 
-        with pytest.raises(com.SettingWithCopyError):
+        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame.*"
+        with pytest.raises(com.SettingWithCopyError, match=msg):
             sliced["C"] = 4.0
 
         assert (float_frame["C"] == 4).all()
@@ -992,7 +994,7 @@ def test_getitem_setitem_fancy_exceptions(self, float_frame):
         with pytest.raises(IndexingError, match="Too many indexers"):
             ix[:, :, :]
 
-        with pytest.raises(IndexingError):
+        with pytest.raises(IndexingError, match="Too many indexers"):
             ix[:, :, :] = 1
 
     def test_getitem_setitem_boolean_misaligned(self, float_frame):
@@ -1071,10 +1073,10 @@ def test_getitem_setitem_float_labels(self):
 
         cp = df.copy()
 
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             cp.iloc[1.0:5] = 0
 
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             result = cp.iloc[1.0:5] == 0  # noqa
 
         assert result.values.all()
@@ -1470,7 +1472,8 @@ def test_iloc_row(self):
 
         # verify slice is view
         # setting it makes it raise/warn
-        with pytest.raises(com.SettingWithCopyError):
+        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame.*"
+        with pytest.raises(com.SettingWithCopyError, match=msg):
             result[2] = 0.0
 
         exp_col = df[2].copy()
@@ -1501,7 +1504,8 @@ def test_iloc_col(self):
 
         # verify slice is view
         # and that we are setting a copy
-        with pytest.raises(com.SettingWithCopyError):
+        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame.*"
+        with pytest.raises(com.SettingWithCopyError, match=msg):
             result[8] = 0.0
 
         assert (df[8] == 0).all()
diff --git a/pandas/tests/frame/indexing/test_where.py b/pandas/tests/frame/indexing/test_where.py
index 507b2e9cd237b..eee754a47fb8c 100644
--- a/pandas/tests/frame/indexing/test_where.py
+++ b/pandas/tests/frame/indexing/test_where.py
@@ -50,7 +50,8 @@ def _check_get(df, cond, check_dtypes=True):
         # check getting
         df = where_frame
         if df is float_string_frame:
-            with pytest.raises(TypeError):
+            msg = "'>' not supported between instances of 'str' and 'int'"
+            with pytest.raises(TypeError, match=msg):
                 df > 0
             return
         cond = df > 0
@@ -114,7 +115,8 @@ def _check_align(df, cond, other, check_dtypes=True):
 
         df = where_frame
         if df is float_string_frame:
-            with pytest.raises(TypeError):
+            msg = "'>' not supported between instances of 'str' and 'int'"
+            with pytest.raises(TypeError, match=msg):
                 df > 0
             return
 
@@ -172,7 +174,8 @@ def _check_set(df, cond, check_dtypes=True):
 
         df = where_frame
         if df is float_string_frame:
-            with pytest.raises(TypeError):
+            msg = "'>' not supported between instances of 'str' and 'int'"
+            with pytest.raises(TypeError, match=msg):
                 df > 0
             return
 
@@ -358,7 +361,8 @@ def test_where_datetime(self):
         )
 
         stamp = datetime(2013, 1, 3)
-        with pytest.raises(TypeError):
+        msg = "'>' not supported between instances of 'float' and 'datetime.datetime'"
+        with pytest.raises(TypeError, match=msg):
             df > stamp
 
         result = df[df.iloc[:, :-1] > stamp]
diff --git a/pandas/tests/frame/methods/test_diff.py b/pandas/tests/frame/methods/test_diff.py
index ffdb6d41ebda5..bc52ab8a20bef 100644
--- a/pandas/tests/frame/methods/test_diff.py
+++ b/pandas/tests/frame/methods/test_diff.py
@@ -74,7 +74,7 @@ def test_diff_datetime_axis1(self, tz):
             )
             tm.assert_frame_equal(result, expected)
         else:
-            with pytest.raises(NotImplementedError):
+            with pytest.raises(NotImplementedError, match=""):
                 result = df.diff(axis=1)
 
     def test_diff_timedelta(self):
diff --git a/pandas/tests/frame/methods/test_explode.py b/pandas/tests/frame/methods/test_explode.py
index 76c87ed355492..f4ce766c57d5b 100644
--- a/pandas/tests/frame/methods/test_explode.py
+++ b/pandas/tests/frame/methods/test_explode.py
@@ -9,11 +9,12 @@ def test_error():
     df = pd.DataFrame(
         {"A": pd.Series([[0, 1, 2], np.nan, [], (3, 4)], index=list("abcd")), "B": 1}
     )
-    with pytest.raises(ValueError):
+    msg = r"(:?columns must be unique)|(:?column must be a scalar)"
+    with pytest.raises(ValueError, match=msg):
         df.explode(list("AA"))
 
     df.columns = list("AA")
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError, match=msg):
         df.explode("A")
 
 
diff --git a/pandas/tests/frame/methods/test_isin.py b/pandas/tests/frame/methods/test_isin.py
index 0eb94afc99d94..7900e82505e6c 100644
--- a/pandas/tests/frame/methods/test_isin.py
+++ b/pandas/tests/frame/methods/test_isin.py
@@ -60,10 +60,12 @@ def test_isin_with_string_scalar(self):
             },
             index=["foo", "bar", "baz", "qux"],
         )
-        with pytest.raises(TypeError):
+        msg = r"only list-like or dict-like objects are allowed"
+        r"to be passed to DataFrame.isin\(\), you passed a 'str'"
+        with pytest.raises(TypeError, match=msg):
             df.isin("a")
 
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             df.isin("aaa")
 
     def test_isin_df(self):
@@ -92,7 +94,8 @@ def test_isin_df_dupe_values(self):
         df1 = DataFrame({"A": [1, 2, 3, 4], "B": [2, np.nan, 4, 4]})
         # just cols duped
         df2 = DataFrame([[0, 2], [12, 4], [2, np.nan], [4, 5]], columns=["B", "B"])
-        with pytest.raises(ValueError):
+        msg = "cannot compute isin with a duplicate axis."
+        with pytest.raises(ValueError, match=msg):
             df1.isin(df2)
 
         # just index duped
@@ -101,12 +104,12 @@ def test_isin_df_dupe_values(self):
             columns=["A", "B"],
             index=[0, 0, 1, 1],
         )
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df1.isin(df2)
 
         # cols and index:
         df2.columns = ["B", "B"]
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df1.isin(df2)
 
     def test_isin_dupe_self(self):
diff --git a/pandas/tests/frame/methods/test_quantile.py b/pandas/tests/frame/methods/test_quantile.py
index 64461c08d34f4..9c52e8ec5620f 100644
--- a/pandas/tests/frame/methods/test_quantile.py
+++ b/pandas/tests/frame/methods/test_quantile.py
@@ -75,7 +75,8 @@ def test_quantile_axis_mixed(self):
         tm.assert_series_equal(result, expected)
 
         # must raise
-        with pytest.raises(TypeError):
+        msg = "'<' not supported between instances of 'Timestamp' and 'float'"
+        with pytest.raises(TypeError, match=msg):
             df.quantile(0.5, axis=1, numeric_only=False)
 
     def test_quantile_axis_parameter(self):
diff --git a/pandas/tests/frame/methods/test_replace.py b/pandas/tests/frame/methods/test_replace.py
index 92b74c4409d7d..57f000a45a619 100644
--- a/pandas/tests/frame/methods/test_replace.py
+++ b/pandas/tests/frame/methods/test_replace.py
@@ -1308,7 +1308,9 @@ def test_categorical_replace_with_dict(self, replace_dict, final_data):
         expected["b"] = expected["b"].cat.set_categories([1, 2, 3])
         result = df.replace(replace_dict, 3)
         tm.assert_frame_equal(result, expected)
-        with pytest.raises(AssertionError):
+        msg = r"Attributes of DataFrame.iloc\[:, 0\]"
+        r"\(column name=\"a\"\) are different.*"
+        with pytest.raises(AssertionError, match=msg):
             # ensure non-inplace call does not affect original
             tm.assert_frame_equal(df, expected)
         df.replace(replace_dict, 3, inplace=True)
diff --git a/pandas/tests/frame/methods/test_round.py b/pandas/tests/frame/methods/test_round.py
index 0865e03cedc50..6dcdf49e93729 100644
--- a/pandas/tests/frame/methods/test_round.py
+++ b/pandas/tests/frame/methods/test_round.py
@@ -34,7 +34,8 @@ def test_round(self):
 
         # Round with a list
         round_list = [1, 2]
-        with pytest.raises(TypeError):
+        msg = "decimals must be an integer, a dict-like or a Series"
+        with pytest.raises(TypeError, match=msg):
             df.round(round_list)
 
         # Round with a dictionary
@@ -57,34 +58,37 @@ def test_round(self):
 
         # float input to `decimals`
         non_int_round_dict = {"col1": 1, "col2": 0.5}
-        with pytest.raises(TypeError):
+        msg = "integer argument expected, got float"
+        with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_dict)
 
         # String input
         non_int_round_dict = {"col1": 1, "col2": "foo"}
-        with pytest.raises(TypeError):
+        msg = r"an integer is required \(got type str\)"
+        with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_dict)
 
         non_int_round_Series = Series(non_int_round_dict)
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_Series)
 
         # List input
         non_int_round_dict = {"col1": 1, "col2": [1, 2]}
-        with pytest.raises(TypeError):
+        msg = r"an integer is required \(got type list\)"
+        with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_dict)
 
         non_int_round_Series = Series(non_int_round_dict)
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_Series)
 
         # Non integer Series inputs
         non_int_round_Series = Series(non_int_round_dict)
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_Series)
 
         non_int_round_Series = Series(non_int_round_dict)
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             df.round(non_int_round_Series)
 
         # Negative numbers
@@ -103,7 +107,8 @@ def test_round(self):
             {"col1": [1.123, 2.123, 3.123], "col2": [1.2, 2.2, 3.2]}
         )
 
-        with pytest.raises(TypeError):
+        msg = "integer argument expected, got float"
+        with pytest.raises(TypeError, match=msg):
             df.round(nan_round_Series)
 
         # Make sure this doesn't break existing Series.round
diff --git a/pandas/tests/frame/methods/test_sort_values.py b/pandas/tests/frame/methods/test_sort_values.py
index 96f4d6ed90d6b..5a25d1c2c0894 100644
--- a/pandas/tests/frame/methods/test_sort_values.py
+++ b/pandas/tests/frame/methods/test_sort_values.py
@@ -458,7 +458,7 @@ def test_sort_values_na_position_with_categories_raises(self):
             }
         )
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match="invalid na_position: bad_position"):
             df.sort_values(by="c", ascending=False, na_position="bad_position")
 
     @pytest.mark.parametrize("inplace", [True, False])
diff --git a/pandas/tests/frame/methods/test_to_dict.py b/pandas/tests/frame/methods/test_to_dict.py
index 40393721c4ac6..71373c1fd180f 100644
--- a/pandas/tests/frame/methods/test_to_dict.py
+++ b/pandas/tests/frame/methods/test_to_dict.py
@@ -132,7 +132,11 @@ def test_to_dict(self, mapping):
     def test_to_dict_errors(self, mapping):
         # GH#16122
         df = DataFrame(np.random.randn(3, 3))
-        with pytest.raises(TypeError):
+        msg = (
+            r"(:?unsupported type: <class 'list'\>)"
+            r"|(:?to_dict\(\) only accepts initialized defaultdicts)"
+        )
+        with pytest.raises(TypeError, match=msg):
             df.to_dict(into=mapping)
 
     def test_to_dict_not_unique_warning(self):

From 26b3cdf2c0c301cb341309a1ee13cc32ef41f39d Mon Sep 17 00:00:00 2001
From: Raisa Dzhamtyrova <raya@MacBook-Pro.home>
Date: Mon, 10 Feb 2020 17:14:48 +0000
Subject: [PATCH 2/9] changes to test_boolean.py

---
 pandas/tests/extension/test_boolean.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/extension/test_boolean.py b/pandas/tests/extension/test_boolean.py
index 26795b9d23eff..00ee95f30eb85 100644
--- a/pandas/tests/extension/test_boolean.py
+++ b/pandas/tests/extension/test_boolean.py
@@ -112,7 +112,7 @@ def _check_op(self, s, op, other, op_name, exc=NotImplementedError):
                 # subtraction for bools raises TypeError (but not yet in 1.13)
                 if _np_version_under1p14:
                     pytest.skip("__sub__ does not yet raise in numpy 1.13")
-                msg = r"numpy boolean subtract, the \`-\` operator, is not supported.*"
+                msg = r"numpy boolean subtract, the \`-\` operator.*"
                 with pytest.raises(TypeError, match=msg):
                     op(s, other)
 

From 5e811bda9fbbac45a5f1a6ea7b917206e8af439a Mon Sep 17 00:00:00 2001
From: Raisa Dzhamtyrova <raya@MacBook-Pro.home>
Date: Mon, 10 Feb 2020 21:40:53 +0000
Subject: [PATCH 3/9] split error messages

---
 .../tests/extension/decimal/test_decimal.py   |  2 +-
 .../tests/frame/indexing/test_categorical.py  | 49 ++++++++++---------
 pandas/tests/frame/methods/test_explode.py    |  5 +-
 pandas/tests/frame/methods/test_isin.py       |  6 ++-
 pandas/tests/frame/methods/test_replace.py    |  6 ++-
 5 files changed, 36 insertions(+), 32 deletions(-)

diff --git a/pandas/tests/extension/decimal/test_decimal.py b/pandas/tests/extension/decimal/test_decimal.py
index fa69f025bd0fd..f4ffcb8d0f109 100644
--- a/pandas/tests/extension/decimal/test_decimal.py
+++ b/pandas/tests/extension/decimal/test_decimal.py
@@ -146,8 +146,8 @@ class TestMissing(BaseDecimal, base.BaseMissingTests):
 
 class Reduce:
     def check_reduce(self, s, op_name, skipna):
+
         if op_name in ["median", "skew", "kurt"]:
-            # breakpoint()
             msg = r"decimal does not support the .* operation"
             with pytest.raises(NotImplementedError, match=msg):
                 getattr(s, op_name)(skipna=skipna)
diff --git a/pandas/tests/frame/indexing/test_categorical.py b/pandas/tests/frame/indexing/test_categorical.py
index e2a7b11eb7a13..f5b3f980cc534 100644
--- a/pandas/tests/frame/indexing/test_categorical.py
+++ b/pandas/tests/frame/indexing/test_categorical.py
@@ -115,11 +115,12 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        msg = (
-            r"(:?Cannot setitem on a Categorical with a new category.*)"
-            r"|(:?Cannot set a Categorical with another, without identical categories)"
+        msg1 = (
+            "Cannot setitem on a Categorical with a new category, "
+            "set the categories first"
         )
-        with pytest.raises(ValueError, match=msg):
+        msg2 = "Cannot set a Categorical with another, without identical categories"
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.iloc[2, 0] = "c"
 
@@ -129,7 +130,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_row)
 
         #   - assign a complete row (mixed values) not in categories set
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.iloc[2, :] = ["c", 2]
 
@@ -138,7 +139,7 @@ def test_assigning_ops(self):
         df.iloc[2:4, :] = [["b", 2], ["b", 2]]
         tm.assert_frame_equal(df, exp_multi_row)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.iloc[2:4, :] = [["c", 2], ["c", 2]]
 
@@ -148,12 +149,12 @@ def test_assigning_ops(self):
         df.iloc[2:4, 0] = Categorical(["b", "b"], categories=["a", "b"])
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg2):
             # different categories -> not sure if this should fail or pass
             df = orig.copy()
             df.iloc[2:4, 0] = Categorical(list("bb"), categories=list("abc"))
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg2):
             # different values
             df = orig.copy()
             df.iloc[2:4, 0] = Categorical(list("cc"), categories=list("abc"))
@@ -164,7 +165,7 @@ def test_assigning_ops(self):
         df.iloc[2:4, 0] = ["b", "b"]
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df.iloc[2:4, 0] = ["c", "c"]
 
         #  loc
@@ -179,7 +180,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.loc["j", "cats"] = "c"
 
@@ -189,7 +190,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_row)
 
         #   - assign a complete row (mixed values) not in categories set
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.loc["j", :] = ["c", 2]
 
@@ -198,7 +199,7 @@ def test_assigning_ops(self):
         df.loc["j":"k", :] = [["b", 2], ["b", 2]]
         tm.assert_frame_equal(df, exp_multi_row)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.loc["j":"k", :] = [["c", 2], ["c", 2]]
 
@@ -208,14 +209,14 @@ def test_assigning_ops(self):
         df.loc["j":"k", "cats"] = Categorical(["b", "b"], categories=["a", "b"])
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg2):
             # different categories -> not sure if this should fail or pass
             df = orig.copy()
             df.loc["j":"k", "cats"] = Categorical(
                 ["b", "b"], categories=["a", "b", "c"]
             )
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg2):
             # different values
             df = orig.copy()
             df.loc["j":"k", "cats"] = Categorical(
@@ -228,7 +229,7 @@ def test_assigning_ops(self):
         df.loc["j":"k", "cats"] = ["b", "b"]
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df.loc["j":"k", "cats"] = ["c", "c"]
 
         #  loc
@@ -243,7 +244,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.loc["j", df.columns[0]] = "c"
 
@@ -253,7 +254,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_row)
 
         #   - assign a complete row (mixed values) not in categories set
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.loc["j", :] = ["c", 2]
 
@@ -262,7 +263,7 @@ def test_assigning_ops(self):
         df.loc["j":"k", :] = [["b", 2], ["b", 2]]
         tm.assert_frame_equal(df, exp_multi_row)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.loc["j":"k", :] = [["c", 2], ["c", 2]]
 
@@ -272,14 +273,14 @@ def test_assigning_ops(self):
         df.loc["j":"k", df.columns[0]] = Categorical(["b", "b"], categories=["a", "b"])
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg2):
             # different categories -> not sure if this should fail or pass
             df = orig.copy()
             df.loc["j":"k", df.columns[0]] = Categorical(
                 ["b", "b"], categories=["a", "b", "c"]
             )
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg2):
             # different values
             df = orig.copy()
             df.loc["j":"k", df.columns[0]] = Categorical(
@@ -292,7 +293,7 @@ def test_assigning_ops(self):
         df.loc["j":"k", df.columns[0]] = ["b", "b"]
         tm.assert_frame_equal(df, exp_parts_cats_col)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df.loc["j":"k", df.columns[0]] = ["c", "c"]
 
         # iat
@@ -301,7 +302,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.iat[2, 0] = "c"
 
@@ -312,7 +313,7 @@ def test_assigning_ops(self):
         tm.assert_frame_equal(df, exp_single_cats_value)
 
         #   - assign a single value not in the current categories set
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.at["j", "cats"] = "c"
 
@@ -336,7 +337,7 @@ def test_assigning_ops(self):
         df.at["j", "cats"] = "b"
         tm.assert_frame_equal(df, exp_single_cats_value)
 
-        with pytest.raises(ValueError, match=msg):
+        with pytest.raises(ValueError, match=msg1):
             df = orig.copy()
             df.at["j", "cats"] = "c"
 
diff --git a/pandas/tests/frame/methods/test_explode.py b/pandas/tests/frame/methods/test_explode.py
index f4ce766c57d5b..bad8349ec977b 100644
--- a/pandas/tests/frame/methods/test_explode.py
+++ b/pandas/tests/frame/methods/test_explode.py
@@ -9,12 +9,11 @@ def test_error():
     df = pd.DataFrame(
         {"A": pd.Series([[0, 1, 2], np.nan, [], (3, 4)], index=list("abcd")), "B": 1}
     )
-    msg = r"(:?columns must be unique)|(:?column must be a scalar)"
-    with pytest.raises(ValueError, match=msg):
+    with pytest.raises(ValueError, match="column must be a scalar"):
         df.explode(list("AA"))
 
     df.columns = list("AA")
-    with pytest.raises(ValueError, match=msg):
+    with pytest.raises(ValueError, match="columns must be unique"):
         df.explode("A")
 
 
diff --git a/pandas/tests/frame/methods/test_isin.py b/pandas/tests/frame/methods/test_isin.py
index 7900e82505e6c..f7d3f95d7bbf6 100644
--- a/pandas/tests/frame/methods/test_isin.py
+++ b/pandas/tests/frame/methods/test_isin.py
@@ -60,8 +60,10 @@ def test_isin_with_string_scalar(self):
             },
             index=["foo", "bar", "baz", "qux"],
         )
-        msg = r"only list-like or dict-like objects are allowed"
-        r"to be passed to DataFrame.isin\(\), you passed a 'str'"
+        msg = (
+            r"only list-like or dict-like objects are allowed"
+            r"to be passed to DataFrame.isin\(\), you passed a 'str'"
+        )
         with pytest.raises(TypeError, match=msg):
             df.isin("a")
 
diff --git a/pandas/tests/frame/methods/test_replace.py b/pandas/tests/frame/methods/test_replace.py
index 57f000a45a619..f4cdbb519b872 100644
--- a/pandas/tests/frame/methods/test_replace.py
+++ b/pandas/tests/frame/methods/test_replace.py
@@ -1308,8 +1308,10 @@ def test_categorical_replace_with_dict(self, replace_dict, final_data):
         expected["b"] = expected["b"].cat.set_categories([1, 2, 3])
         result = df.replace(replace_dict, 3)
         tm.assert_frame_equal(result, expected)
-        msg = r"Attributes of DataFrame.iloc\[:, 0\]"
-        r"\(column name=\"a\"\) are different.*"
+        msg = (
+            r"Attributes of DataFrame.iloc\[:, 0\] "
+            r"\(column name=\"a\"\) are different.*"
+        )
         with pytest.raises(AssertionError, match=msg):
             # ensure non-inplace call does not affect original
             tm.assert_frame_equal(df, expected)

From 18b55813f58d470bf5acb074853ab1a5031c8f65 Mon Sep 17 00:00:00 2001
From: Raisa Dzhamtyrova <raya@MacBook-Pro.home>
Date: Mon, 10 Feb 2020 22:13:09 +0000
Subject: [PATCH 4/9] change to test_isin.py

---
 pandas/tests/frame/methods/test_isin.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/frame/methods/test_isin.py b/pandas/tests/frame/methods/test_isin.py
index f7d3f95d7bbf6..65ad76382e5c6 100644
--- a/pandas/tests/frame/methods/test_isin.py
+++ b/pandas/tests/frame/methods/test_isin.py
@@ -61,7 +61,7 @@ def test_isin_with_string_scalar(self):
             index=["foo", "bar", "baz", "qux"],
         )
         msg = (
-            r"only list-like or dict-like objects are allowed"
+            r"only list-like or dict-like objects are allowed "
             r"to be passed to DataFrame.isin\(\), you passed a 'str'"
         )
         with pytest.raises(TypeError, match=msg):

From 965946dec87aa858c5b762ca06031850f5dd82de Mon Sep 17 00:00:00 2001
From: Raisa Dzhamtyrova <raya@MacBook-Pro.home>
Date: Tue, 11 Feb 2020 11:11:25 +0000
Subject: [PATCH 5/9] changes to test_boolean.py and test_indexing.py

---
 pandas/tests/extension/test_boolean.py       | 3 +--
 pandas/tests/frame/indexing/test_indexing.py | 8 ++++----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/pandas/tests/extension/test_boolean.py b/pandas/tests/extension/test_boolean.py
index 00ee95f30eb85..04f49a335292b 100644
--- a/pandas/tests/extension/test_boolean.py
+++ b/pandas/tests/extension/test_boolean.py
@@ -115,7 +115,6 @@ def _check_op(self, s, op, other, op_name, exc=NotImplementedError):
                 msg = r"numpy boolean subtract, the \`-\` operator.*"
                 with pytest.raises(TypeError, match=msg):
                     op(s, other)
-
                 return
 
             result = op(s, other)
@@ -140,7 +139,7 @@ def _check_op(self, s, op, other, op_name, exc=NotImplementedError):
                 expected[result.isna()] = np.nan
             self.assert_series_equal(result, expected)
         else:
-            with pytest.raises(exc, match=msg):
+            with pytest.raises(exc):
                 op(s, other)
 
     def _check_divmod_op(self, s, op, other, exc=None):
diff --git a/pandas/tests/frame/indexing/test_indexing.py b/pandas/tests/frame/indexing/test_indexing.py
index 6d7f1e465dfa3..fcf0a41e0f74e 100644
--- a/pandas/tests/frame/indexing/test_indexing.py
+++ b/pandas/tests/frame/indexing/test_indexing.py
@@ -481,7 +481,7 @@ def test_setitem(self, float_frame):
         # so raise/warn
         smaller = float_frame[:2]
 
-        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame.*"
+        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame"
         with pytest.raises(com.SettingWithCopyError, match=msg):
             smaller["col10"] = ["1", "2"]
 
@@ -866,7 +866,7 @@ def test_fancy_getitem_slice_mixed(self, float_frame, float_string_frame):
         # setting it triggers setting with copy
         sliced = float_frame.iloc[:, -3:]
 
-        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame.*"
+        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame"
         with pytest.raises(com.SettingWithCopyError, match=msg):
             sliced["C"] = 4.0
 
@@ -1472,7 +1472,7 @@ def test_iloc_row(self):
 
         # verify slice is view
         # setting it makes it raise/warn
-        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame.*"
+        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame"
         with pytest.raises(com.SettingWithCopyError, match=msg):
             result[2] = 0.0
 
@@ -1504,7 +1504,7 @@ def test_iloc_col(self):
 
         # verify slice is view
         # and that we are setting a copy
-        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame.*"
+        msg = r"\nA value is trying to be set on a copy of a slice from a DataFrame"
         with pytest.raises(com.SettingWithCopyError, match=msg):
             result[8] = 0.0
 

From c22044c69daa0cd6311e731f1b781ac2478e4e78 Mon Sep 17 00:00:00 2001
From: Raisa Dzhamtyrova <raya@MacBook-Pro.home>
Date: Tue, 11 Feb 2020 15:43:10 +0000
Subject: [PATCH 6/9] revert changes to test_diff.py

---
 pandas/tests/frame/methods/test_diff.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/frame/methods/test_diff.py b/pandas/tests/frame/methods/test_diff.py
index bc52ab8a20bef..ffdb6d41ebda5 100644
--- a/pandas/tests/frame/methods/test_diff.py
+++ b/pandas/tests/frame/methods/test_diff.py
@@ -74,7 +74,7 @@ def test_diff_datetime_axis1(self, tz):
             )
             tm.assert_frame_equal(result, expected)
         else:
-            with pytest.raises(NotImplementedError, match=""):
+            with pytest.raises(NotImplementedError):
                 result = df.diff(axis=1)
 
     def test_diff_timedelta(self):

From f1686fce2791ba5a393362017f9f1f6a8ecfd753 Mon Sep 17 00:00:00 2001
From: Raisa Dzhamtyrova <raya@MacBook-Pro.home>
Date: Tue, 11 Feb 2020 16:46:34 +0000
Subject: [PATCH 7/9] cleanups to the code

---
 pandas/tests/extension/json/test_json.py   | 2 +-
 pandas/tests/extension/test_boolean.py     | 2 +-
 pandas/tests/frame/methods/test_isin.py    | 2 +-
 pandas/tests/frame/methods/test_replace.py | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/pandas/tests/extension/json/test_json.py b/pandas/tests/extension/json/test_json.py
index 6a85c4efe29d4..d086896fb09c3 100644
--- a/pandas/tests/extension/json/test_json.py
+++ b/pandas/tests/extension/json/test_json.py
@@ -136,7 +136,7 @@ def test_custom_asserts(self):
         self.assert_frame_equal(a.to_frame(), a.to_frame())
 
         b = pd.Series(data.take([0, 0, 1]))
-        msg = r"ExtensionArray are different.*"
+        msg = r"ExtensionArray are different"
         with pytest.raises(AssertionError, match=msg):
             self.assert_series_equal(a, b)
 
diff --git a/pandas/tests/extension/test_boolean.py b/pandas/tests/extension/test_boolean.py
index 04f49a335292b..a354075809fba 100644
--- a/pandas/tests/extension/test_boolean.py
+++ b/pandas/tests/extension/test_boolean.py
@@ -112,7 +112,7 @@ def _check_op(self, s, op, other, op_name, exc=NotImplementedError):
                 # subtraction for bools raises TypeError (but not yet in 1.13)
                 if _np_version_under1p14:
                     pytest.skip("__sub__ does not yet raise in numpy 1.13")
-                msg = r"numpy boolean subtract, the \`-\` operator.*"
+                msg = r"numpy boolean subtract, the \`-\` operator"
                 with pytest.raises(TypeError, match=msg):
                     op(s, other)
                 return
diff --git a/pandas/tests/frame/methods/test_isin.py b/pandas/tests/frame/methods/test_isin.py
index 65ad76382e5c6..6307738021f68 100644
--- a/pandas/tests/frame/methods/test_isin.py
+++ b/pandas/tests/frame/methods/test_isin.py
@@ -96,7 +96,7 @@ def test_isin_df_dupe_values(self):
         df1 = DataFrame({"A": [1, 2, 3, 4], "B": [2, np.nan, 4, 4]})
         # just cols duped
         df2 = DataFrame([[0, 2], [12, 4], [2, np.nan], [4, 5]], columns=["B", "B"])
-        msg = "cannot compute isin with a duplicate axis."
+        msg = r"cannot compute isin with a duplicate axis\."
         with pytest.raises(ValueError, match=msg):
             df1.isin(df2)
 
diff --git a/pandas/tests/frame/methods/test_replace.py b/pandas/tests/frame/methods/test_replace.py
index f4cdbb519b872..d1ba0c0a6ea8f 100644
--- a/pandas/tests/frame/methods/test_replace.py
+++ b/pandas/tests/frame/methods/test_replace.py
@@ -1310,7 +1310,7 @@ def test_categorical_replace_with_dict(self, replace_dict, final_data):
         tm.assert_frame_equal(result, expected)
         msg = (
             r"Attributes of DataFrame.iloc\[:, 0\] "
-            r"\(column name=\"a\"\) are different.*"
+            r"\(column name=\"a\"\) are different"
         )
         with pytest.raises(AssertionError, match=msg):
             # ensure non-inplace call does not affect original

From dda42be7a2ee8dd0c556cd79923f4ee7f16f6683 Mon Sep 17 00:00:00 2001
From: Raisa Dzhamtyrova <raya@MacBook-Pro.home>
Date: Wed, 12 Feb 2020 15:30:58 +0000
Subject: [PATCH 8/9] changes to test_boolean.py and test_replace.py

---
 pandas/tests/extension/test_boolean.py     | 2 +-
 pandas/tests/frame/methods/test_replace.py | 6 +-----
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/pandas/tests/extension/test_boolean.py b/pandas/tests/extension/test_boolean.py
index a354075809fba..e2331b69916fb 100644
--- a/pandas/tests/extension/test_boolean.py
+++ b/pandas/tests/extension/test_boolean.py
@@ -112,7 +112,7 @@ def _check_op(self, s, op, other, op_name, exc=NotImplementedError):
                 # subtraction for bools raises TypeError (but not yet in 1.13)
                 if _np_version_under1p14:
                     pytest.skip("__sub__ does not yet raise in numpy 1.13")
-                msg = r"numpy boolean subtract, the \`-\` operator"
+                msg = r"numpy boolean subtract"
                 with pytest.raises(TypeError, match=msg):
                     op(s, other)
                 return
diff --git a/pandas/tests/frame/methods/test_replace.py b/pandas/tests/frame/methods/test_replace.py
index d1ba0c0a6ea8f..92b74c4409d7d 100644
--- a/pandas/tests/frame/methods/test_replace.py
+++ b/pandas/tests/frame/methods/test_replace.py
@@ -1308,11 +1308,7 @@ def test_categorical_replace_with_dict(self, replace_dict, final_data):
         expected["b"] = expected["b"].cat.set_categories([1, 2, 3])
         result = df.replace(replace_dict, 3)
         tm.assert_frame_equal(result, expected)
-        msg = (
-            r"Attributes of DataFrame.iloc\[:, 0\] "
-            r"\(column name=\"a\"\) are different"
-        )
-        with pytest.raises(AssertionError, match=msg):
+        with pytest.raises(AssertionError):
             # ensure non-inplace call does not affect original
             tm.assert_frame_equal(df, expected)
         df.replace(replace_dict, 3, inplace=True)

From f54510d8c7b1adb6e57978df526d139533bfbd1d Mon Sep 17 00:00:00 2001
From: Raisa Dzhamtyrova <raya@MacBook-Pro.home>
Date: Tue, 18 Feb 2020 09:12:46 +0000
Subject: [PATCH 9/9] change error message in test_to_dict.py

---
 pandas/tests/frame/methods/test_to_dict.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pandas/tests/frame/methods/test_to_dict.py b/pandas/tests/frame/methods/test_to_dict.py
index 71373c1fd180f..cd9bd169322fd 100644
--- a/pandas/tests/frame/methods/test_to_dict.py
+++ b/pandas/tests/frame/methods/test_to_dict.py
@@ -132,9 +132,11 @@ def test_to_dict(self, mapping):
     def test_to_dict_errors(self, mapping):
         # GH#16122
         df = DataFrame(np.random.randn(3, 3))
-        msg = (
-            r"(:?unsupported type: <class 'list'\>)"
-            r"|(:?to_dict\(\) only accepts initialized defaultdicts)"
+        msg = "|".join(
+            [
+                "unsupported type: <class 'list'>",
+                r"to_dict\(\) only accepts initialized defaultdicts",
+            ]
         )
         with pytest.raises(TypeError, match=msg):
             df.to_dict(into=mapping)