TST: More explicit test patterns (#54463)

Author: mroeschke

pandas/tests/arithmetic/test_datetime64.py

@@ -414,8 +414,7 @@ def test_dti_cmp_datetimelike(self, other, tz_naive_fixture):
         dti = date_range("2016-01-01", periods=2, tz=tz)
         if tz is not None:
             if isinstance(other, np.datetime64):
-                # no tzaware version available
-                return
+                pytest.skip("no tzaware version available")
             other = localize_pydatetime(other, dti.tzinfo)
 
         result = dti == other
@@ -1080,13 +1079,14 @@ def test_dt64arr_add_dtlike_raises(self, tz_naive_fixture, box_with_array):
     @pytest.mark.parametrize("freq", ["H", "D", "W", "M", "MS", "Q", "B", None])
     @pytest.mark.parametrize("dtype", [None, "uint8"])
     def test_dt64arr_addsub_intlike(
-        self, dtype, box_with_array, freq, tz_naive_fixture
+        self, request, dtype, box_with_array, freq, tz_naive_fixture
     ):
         # GH#19959, GH#19123, GH#19012
         tz = tz_naive_fixture
         if box_with_array is pd.DataFrame:
-            # alignment headaches
-            return
+            request.node.add_marker(
+                pytest.mark.xfail(raises=ValueError, reason="Axis alignment fails")
+            )
 
         if freq is None:
             dti = DatetimeIndex(["NaT", "2017-04-05 06:07:08"], tz=tz)

pandas/tests/arithmetic/test_numeric.py

@@ -377,7 +377,7 @@ def test_divmod_zero(self, zero, numeric_idx):
     def test_div_negative_zero(self, zero, numeric_idx, op):
         # Check that -1 / -0.0 returns np.inf, not -np.inf
         if numeric_idx.dtype == np.uint64:
-            return
+            pytest.skip(f"Not relevant for {numeric_idx.dtype}")
         idx = numeric_idx - 3
 
         expected = Index([-np.inf, -np.inf, -np.inf, np.nan, np.inf], dtype=np.float64)

pandas/tests/arithmetic/test_timedelta64.py

@@ -1002,7 +1002,7 @@ def test_td64arr_add_sub_datetimelike_scalar(
             ts = dt_scalar.to_pydatetime()
         elif cls is np.datetime64:
             if tz_naive_fixture is not None:
-                return
+                pytest.skip(f"{cls} doesn support {tz_naive_fixture}")
             ts = dt_scalar.to_datetime64()
         else:
             ts = dt_scalar

pandas/tests/frame/methods/test_to_csv.py

@@ -674,10 +674,7 @@ def create_cols(name):
 
         # add in some nans
         df_float.iloc[30:50, 1:3] = np.nan
-
-        # ## this is a bug in read_csv right now ####
-        # df_dt.loc[30:50,1:3] = np.nan
-        # FIXME: don't leave commented-out
+        df_dt.iloc[30:50, 1:3] = np.nan
 
         df = pd.concat([df_float, df_int, df_bool, df_object, df_dt], axis=1)
 

pandas/tests/frame/test_arithmetic.py

@@ -1766,7 +1766,12 @@ def test_inplace_ops_identity(self):
         [
             "add",
             "and",
-            "div",
+            pytest.param(
+                "div",
+                marks=pytest.mark.xfail(
+                    raises=AttributeError, reason="__idiv__ not implemented"
+                ),
+            ),
             "floordiv",
             "mod",
             "mul",
@@ -1778,9 +1783,6 @@ def test_inplace_ops_identity(self):
         ],
     )
     def test_inplace_ops_identity2(self, op):
-        if op == "div":
-            return
-
         df = DataFrame({"a": [1.0, 2.0, 3.0], "b": [1, 2, 3]})
 
         operand = 2

pandas/tests/frame/test_constructors.py

@@ -2514,7 +2514,7 @@ def test_dict_nocopy(
         b = np.array([3, 4], dtype=any_numpy_dtype)
         if b.dtype.kind in ["S", "U"]:
             # These get cast, making the checks below more cumbersome
-            return
+            pytest.skip(f"{b.dtype} get cast, making the checks below more cumbersome")
 
         c = pd.array([1, 2], dtype=any_numeric_ea_dtype)
         c_orig = c.copy()

pandas/tests/groupby/test_api.py

@@ -205,8 +205,7 @@ def test_frame_consistency(groupby_func):
 def test_series_consistency(request, groupby_func):
     # GH#48028
     if groupby_func in ("first", "last"):
-        # first and last are entirely different between Series and groupby
-        return
+        pytest.skip("first and last are entirely different between Series and groupby")
 
     if groupby_func in ("cumcount", "corrwith", "ngroup"):
         assert not hasattr(Series, groupby_func)

pandas/tests/groupby/transform/test_transform.py

@@ -775,9 +775,8 @@ def frame_mi(frame):
         {"by": np.random.default_rng(2).integers(0, 50, size=10).astype(float)},
         {"level": 0},
         {"by": "string"},
-        # {"by": 'string_missing'}]:
-        # {"by": ['int','string']}]:
-        # TODO: remove or enable commented-out code
+        pytest.param({"by": "string_missing"}, marks=pytest.mark.xfail),
+        {"by": ["int", "string"]},
     ],
 )
 def test_cython_transform_frame(request, op, args, targop, df_fix, gb_target):
@@ -825,9 +824,9 @@ def test_cython_transform_frame(request, op, args, targop, df_fix, gb_target):
         {"by": np.random.default_rng(2).integers(0, 50, size=10).astype(float)},
         {"level": 0},
         {"by": "string"},
-        # {"by": 'string_missing'}]:
-        # {"by": ['int','string']}]:
-        # TODO: remove or enable commented-out code
+        # TODO: create xfail condition given other params
+        # {"by": 'string_missing'},
+        {"by": ["int", "string"]},
     ],
 )
 @pytest.mark.parametrize(

pandas/tests/indexes/multi/test_setops.py

@@ -626,8 +626,7 @@ def test_union_with_duplicates_keep_ea_dtype(dupe_val, any_numeric_ea_dtype):
 def test_union_duplicates(index, request):
     # GH#38977
     if index.empty or isinstance(index, (IntervalIndex, CategoricalIndex)):
-        # No duplicates in empty indexes
-        return
+        pytest.skip(f"No duplicates in an empty {type(index).__name__}")
 
     values = index.unique().values.tolist()
     mi1 = MultiIndex.from_arrays([values, [1] * len(values)])

pandas/tests/indexes/test_any_index.py

@@ -34,7 +34,7 @@ def test_hash_error(index):
 
 def test_mutability(index):
     if not len(index):
-        return
+        pytest.skip("Test doesn't make sense for empty index")
     msg = "Index does not support mutable operations"
     with pytest.raises(TypeError, match=msg):
         index[0] = index[0]