30999 fix bare pytest raises (#33925)

andresmcneill · web-flow · commit 592db7df8def · 2020-05-01T15:30:30.000-04:00
diff --git a/pandas/tests/series/methods/test_asof.py b/pandas/tests/series/methods/test_asof.py
@@ -148,14 +148,14 @@ def test_errors(self):
 
         # non-monotonic
         assert not s.index.is_monotonic
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match="requires a sorted index"):
             s.asof(s.index[0])
 
         # subset with Series
         N = 10
         rng = date_range("1/1/1990", periods=N, freq="53s")
         s = Series(np.random.randn(N), index=rng)
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match="not valid for Series"):
             s.asof(s.index[0], subset="foo")
 
     def test_all_nans(self):
diff --git a/pandas/tests/series/methods/test_droplevel.py b/pandas/tests/series/methods/test_droplevel.py
@@ -15,5 +15,5 @@ def test_droplevel(self):
         result = ser.droplevel("b", axis="index")
         tm.assert_series_equal(result, expected)
         # test that droplevel raises ValueError on axis != 0
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match="No axis named columns"):
             ser.droplevel(1, axis="columns")
diff --git a/pandas/tests/series/methods/test_tz_localize.py b/pandas/tests/series/methods/test_tz_localize.py
@@ -35,7 +35,7 @@ def test_series_tz_localize_ambiguous_bool(self):
         expected0 = Series([expected0])
         expected1 = Series([expected1])
 
-        with pytest.raises(pytz.AmbiguousTimeError):
+        with tm.external_error_raised(pytz.AmbiguousTimeError):
             ser.dt.tz_localize("US/Central")
 
         result = ser.dt.tz_localize("US/Central", ambiguous=True)
@@ -66,10 +66,10 @@ def test_series_tz_localize_nonexistent(self, tz, method, exp):
         dti = date_range(start="2015-03-29 02:00:00", periods=n, freq="min")
         s = Series(1, dti)
         if method == "raise":
-            with pytest.raises(pytz.NonExistentTimeError):
+            with tm.external_error_raised(pytz.NonExistentTimeError):
                 s.tz_localize(tz, nonexistent=method)
         elif exp == "invalid":
-            with pytest.raises(ValueError):
+            with pytest.raises(ValueError, match="argument must be one of"):
                 dti.tz_localize(tz, nonexistent=method)
         else:
             result = s.tz_localize(tz, nonexistent=method)
diff --git a/pandas/tests/series/test_apply.py b/pandas/tests/series/test_apply.py
@@ -248,18 +248,21 @@ def test_transform(self, string_series):
 
     def test_transform_and_agg_error(self, string_series):
         # we are trying to transform with an aggregator
-        with pytest.raises(ValueError):
+        msg = "transforms cannot produce aggregated results"
+        with pytest.raises(ValueError, match=msg):
             string_series.transform(["min", "max"])
 
-        with pytest.raises(ValueError):
+        msg = "cannot combine transform and aggregation"
+        with pytest.raises(ValueError, match=msg):
             with np.errstate(all="ignore"):
                 string_series.agg(["sqrt", "max"])
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             with np.errstate(all="ignore"):
                 string_series.transform(["sqrt", "max"])
 
-        with pytest.raises(ValueError):
+        msg = "cannot perform both aggregation and transformation"
+        with pytest.raises(ValueError, match=msg):
             with np.errstate(all="ignore"):
                 string_series.agg({"foo": np.sqrt, "bar": "sum"})
 
diff --git a/pandas/tests/series/test_arithmetic.py b/pandas/tests/series/test_arithmetic.py
@@ -335,12 +335,13 @@ class TestSeriesComparison:
     def test_comparison_different_length(self):
         a = Series(["a", "b", "c"])
         b = Series(["b", "a"])
-        with pytest.raises(ValueError):
+        msg = "only compare identically-labeled Series"
+        with pytest.raises(ValueError, match=msg):
             a < b
 
         a = Series([1, 2])
         b = Series([2, 3, 4])
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             a == b
 
     @pytest.mark.parametrize("opname", ["eq", "ne", "gt", "lt", "ge", "le"])
@@ -474,37 +475,40 @@ def test_categorical_comparisons(self):
         assert (~(f == a) == (f != a)).all()
 
         # non-equality is not comparable
-        with pytest.raises(TypeError):
+        msg = "can only compare equality or not"
+        with pytest.raises(TypeError, match=msg):
             a < b
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             b < a
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             a > b
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             b > a
 
     def test_unequal_categorical_comparison_raises_type_error(self):
         # unequal comparison should raise for unordered cats
         cat = Series(Categorical(list("abc")))
-        with pytest.raises(TypeError):
+        msg = "can only compare equality or not"
+        with pytest.raises(TypeError, match=msg):
             cat > "b"
 
         cat = Series(Categorical(list("abc"), ordered=False))
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             cat > "b"
 
         # https://github.com/pandas-dev/pandas/issues/9836#issuecomment-92123057
         # and following comparisons with scalars not in categories should raise
         # for unequal comps, but not for equal/not equal
         cat = Series(Categorical(list("abc"), ordered=True))
 
-        with pytest.raises(TypeError):
+        msg = "Cannot compare a Categorical for op.+with a scalar"
+        with pytest.raises(TypeError, match=msg):
             cat < "d"
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             cat > "d"
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             "d" < cat
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             "d" > cat
 
         tm.assert_series_equal(cat == "d", Series([False, False, False]))
@@ -668,10 +672,11 @@ def test_series_add_aware_naive_raises(self):
 
         ser_utc = ser.tz_localize("utc")
 
-        with pytest.raises(Exception):
+        msg = "Cannot join tz-naive with tz-aware DatetimeIndex"
+        with pytest.raises(Exception, match=msg):
             ser + ser_utc
 
-        with pytest.raises(Exception):
+        with pytest.raises(Exception, match=msg):
             ser_utc + ser
 
     def test_datetime_understood(self):
diff --git a/pandas/tests/series/test_datetime_values.py b/pandas/tests/series/test_datetime_values.py
@@ -244,8 +244,9 @@ def get_dir(s):
             s.dt.hour = 5
 
         # trying to set a copy
+        msg = "modifications to a property of a datetimelike.+not supported"
         with pd.option_context("chained_assignment", "raise"):
-            with pytest.raises(com.SettingWithCopyError):
+            with pytest.raises(com.SettingWithCopyError, match=msg):
                 s.dt.hour[0] = 5
 
     @pytest.mark.parametrize(
@@ -311,7 +312,7 @@ def test_dt_round_tz_ambiguous(self, method):
         tm.assert_series_equal(result, expected)
 
         # raise
-        with pytest.raises(pytz.AmbiguousTimeError):
+        with tm.external_error_raised(pytz.AmbiguousTimeError):
             getattr(df1.date.dt, method)("H", ambiguous="raise")
 
     @pytest.mark.parametrize(
diff --git a/pandas/tests/series/test_operators.py b/pandas/tests/series/test_operators.py
@@ -121,23 +121,25 @@ def test_logical_operators_int_dtype_with_float(self):
         # GH#9016: support bitwise op for integer types
         s_0123 = Series(range(4), dtype="int64")
 
-        with pytest.raises(TypeError):
+        msg = "Cannot perform.+with a dtyped.+array and scalar of type"
+        with pytest.raises(TypeError, match=msg):
             s_0123 & np.NaN
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             s_0123 & 3.14
-        with pytest.raises(TypeError):
+        msg = "unsupported operand type.+for &:"
+        with pytest.raises(TypeError, match=msg):
             s_0123 & [0.1, 4, 3.14, 2]
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             s_0123 & np.array([0.1, 4, 3.14, 2])
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             s_0123 & Series([0.1, 4, -3.14, 2])
 
     def test_logical_operators_int_dtype_with_str(self):
         s_1111 = Series([1] * 4, dtype="int8")
-
-        with pytest.raises(TypeError):
+        msg = "Cannot perform 'and_' with a dtyped.+array and scalar of type"
+        with pytest.raises(TypeError, match=msg):
             s_1111 & "a"
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match="unsupported operand.+for &"):
             s_1111 & ["a", "b", "c", "d"]
 
     def test_logical_operators_int_dtype_with_bool(self):
@@ -255,7 +257,8 @@ def test_logical_operators_int_dtype_with_bool_dtype_and_reindex(self):
     def test_scalar_na_logical_ops_corners(self):
         s = Series([2, 3, 4, 5, 6, 7, 8, 9, 10])
 
-        with pytest.raises(TypeError):
+        msg = "Cannot perform.+with a dtyped.+array and scalar of type"
+        with pytest.raises(TypeError, match=msg):
             s & datetime(2005, 1, 1)
 
         s = Series([2, 3, 4, 5, 6, 7, 8, 9, datetime(2005, 1, 1)])
@@ -451,8 +454,9 @@ def test_logical_ops_label_based(self):
             expected = Series([True, True, True], index=index)
             tm.assert_series_equal(result, expected)
 
+        msg = "Cannot perform.+with a dtyped.+array and scalar of type"
         for v in [np.nan, "foo"]:
-            with pytest.raises(TypeError):
+            with pytest.raises(TypeError, match=msg):
                 t | v
 
         for v in [False, 0]:
@@ -469,8 +473,9 @@ def test_logical_ops_label_based(self):
             result = Series([True, False, True], index=index) & v
             expected = Series([False, False, False], index=index)
             tm.assert_series_equal(result, expected)
+        msg = "Cannot perform.+with a dtyped.+array and scalar of type"
         for v in [np.nan]:
-            with pytest.raises(TypeError):
+            with pytest.raises(TypeError, match=msg):
                 t & v
 
     def test_logical_ops_df_compat(self):
diff --git a/pandas/tests/tools/test_to_time.py b/pandas/tests/tools/test_to_time.py
@@ -46,7 +46,8 @@ def test_parsers_time(self):
         res = to_time(arg, format="%I:%M%p", errors="ignore")
         tm.assert_numpy_array_equal(res, np.array(arg, dtype=np.object_))
 
-        with pytest.raises(ValueError):
+        msg = "Cannot convert.+to a time with given format"
+        with pytest.raises(ValueError, match=msg):
             to_time(arg, format="%I:%M%p", errors="raise")
 
         tm.assert_series_equal(
