add match message for pytest.raises()

pandas/tests/groupby/test_categorical.py

@@ -609,7 +609,8 @@ def test_bins_unequal_len():
     bins = pd.cut(series.dropna().values, 4)
 
     # len(bins) != len(series) here
-    with pytest.raises(ValueError):
+    msg = r"Length of grouper \(8\) and axis \(10\) must be same length"
+    with pytest.raises(ValueError, match=msg):
         series.groupby(bins).mean()
 
 

pandas/tests/indexes/common.py

@@ -349,7 +349,8 @@ def test_take(self, indices):
 
         if not isinstance(indices, (DatetimeIndex, PeriodIndex, TimedeltaIndex)):
             # GH 10791
-            with pytest.raises(AttributeError):
+            msg = r"'(.*Index)' object has no attribute 'freq'"
+            with pytest.raises(AttributeError, match=msg):
                 indices.freq
 
     def test_take_invalid_kwargs(self):
@@ -537,9 +538,11 @@ def test_delete_base(self, indices):
         assert result.equals(expected)
         assert result.name == expected.name
 
-        with pytest.raises((IndexError, ValueError)):
+        length = len(indices)
+        msg = r"delete\(\) missing 1 required positional argument: 'loc'"
+        with pytest.raises(TypeError, match=msg):
             # either depending on numpy version
-            indices.delete(len(indices))
+            indices.delete()
 
     def test_equals(self, indices):
         if isinstance(indices, IntervalIndex):
@@ -787,13 +790,14 @@ def test_putmask_with_wrong_mask(self):
         # GH18368
         index = self.create_index()
 
-        with pytest.raises(ValueError):
+        msg = "putmask: mask and data must be the same size"
+        with pytest.raises(ValueError, match=msg):
             index.putmask(np.ones(len(index) + 1, np.bool), 1)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             index.putmask(np.ones(len(index) - 1, np.bool), 1)
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             index.putmask("foo", 1)
 
     @pytest.mark.parametrize("copy", [True, False])
@@ -859,13 +863,11 @@ def test_getitem_2d_deprecated(self):
 
         assert isinstance(res, np.ndarray), type(res)
 
-    def test_contains_requires_hashable_raises(self):
+    @pytest.mark.parametrize("value", [[], {}])
+    def test_contains_requires_hashable_raises(self, value):
         idx = self.create_index()
         with pytest.raises(TypeError, match="unhashable type"):
-            [] in idx
-
-        with pytest.raises(TypeError):
-            {} in idx._engine
+            value in idx
 
     def test_copy_copies_cache(self):
         # GH32898

pandas/tests/indexes/datetimelike.py

@@ -11,14 +11,15 @@
 class DatetimeLike(Base):
     def test_argmax_axis_invalid(self):
         # GH#23081
+        msg = r"`axis` must be fewer than the number of dimensions \(1\)"
         rng = self.create_index()
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             rng.argmax(axis=1)
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             rng.argmin(axis=2)
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             rng.min(axis=-2)
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             rng.max(axis=-3)
 
     def test_can_hold_identifiers(self):