Fix more tests

Author: phofl

pandas/tests/frame/test_arithmetic.py

@@ -417,8 +417,8 @@ def test_bool_flex_frame_complex_dtype(self):
 
     def test_bool_flex_frame_object_dtype(self):
         # corner, dtype=object
-        df1 = DataFrame({"col": ["foo", np.nan, "bar"]})
-        df2 = DataFrame({"col": ["foo", datetime.now(), "bar"]})
+        df1 = DataFrame({"col": ["foo", np.nan, "bar"]}, dtype=object)
+        df2 = DataFrame({"col": ["foo", datetime.now(), "bar"]}, dtype=object)
         result = df1.ne(df2)
         exp = DataFrame({"col": [False, True, False]})
         tm.assert_frame_equal(result, exp)
@@ -1997,7 +1997,12 @@ def test_dataframe_blockwise_slicelike():
     "df, col_dtype",
     [
         (DataFrame([[1.0, 2.0], [4.0, 5.0]], columns=list("ab")), "float64"),
-        (DataFrame([[1.0, "b"], [4.0, "b"]], columns=list("ab")), "object"),
+        (
+            DataFrame([[1.0, "b"], [4.0, "b"]], columns=list("ab")).astype(
+                {"b": object}
+            ),
+            "object",
+        ),
     ],
 )
 def test_dataframe_operation_with_non_numeric_types(df, col_dtype):

pandas/tests/frame/test_query_eval.py

@@ -1031,7 +1031,7 @@ def test_query_with_string_columns(self, parser, engine):
             with pytest.raises(NotImplementedError, match=msg):
                 df.query("a in b and c < d", parser=parser, engine=engine)
 
-    def test_object_array_eq_ne(self, parser, engine):
+    def test_object_array_eq_ne(self, parser, engine, using_infer_string):
         df = DataFrame(
             {
                 "a": list("aaaabbbbcccc"),
@@ -1040,11 +1040,14 @@ def test_object_array_eq_ne(self, parser, engine):
                 "d": np.random.default_rng(2).integers(9, size=12),
             }
         )
-        res = df.query("a == b", parser=parser, engine=engine)
+        warning = RuntimeWarning if using_infer_string and engine == "numexpr" else None
+        with tm.assert_produces_warning(warning):
+            res = df.query("a == b", parser=parser, engine=engine)
         exp = df[df.a == df.b]
         tm.assert_frame_equal(res, exp)
 
-        res = df.query("a != b", parser=parser, engine=engine)
+        with tm.assert_produces_warning(warning):
+            res = df.query("a != b", parser=parser, engine=engine)
         exp = df[df.a != df.b]
         tm.assert_frame_equal(res, exp)
 
@@ -1083,12 +1086,16 @@ def test_query_with_nested_special_character(self, parser, engine):
             [">=", operator.ge],
         ],
     )
-    def test_query_lex_compare_strings(self, parser, engine, op, func):
+    def test_query_lex_compare_strings(
+        self, parser, engine, op, func, using_infer_string
+    ):
         a = Series(np.random.default_rng(2).choice(list("abcde"), 20))
         b = Series(np.arange(a.size))
         df = DataFrame({"X": a, "Y": b})
 
-        res = df.query(f'X {op} "d"', engine=engine, parser=parser)
+        warning = RuntimeWarning if using_infer_string and engine == "numexpr" else None
+        with tm.assert_produces_warning(warning):
+            res = df.query(f'X {op} "d"', engine=engine, parser=parser)
         expected = df[func(df.X, "d")]
         tm.assert_frame_equal(res, expected)
 

pandas/tests/frame/test_reductions.py

@@ -1888,7 +1888,7 @@ def test_minmax_extensionarray(method, numeric_only):
     expected = Series(
         [getattr(int64_info, method)],
         dtype="Int64",
-        index=Index(["Int64"], dtype="object"),
+        index=Index(["Int64"]),
     )
     tm.assert_series_equal(result, expected)
 
@@ -1906,7 +1906,7 @@ def test_prod_sum_min_count_mixed_object():
     df = DataFrame([1, "a", True])
 
     result = df.prod(axis=0, min_count=1, numeric_only=False)
-    expected = Series(["a"])
+    expected = Series(["a"], dtype=object)
     tm.assert_series_equal(result, expected)
 
     msg = re.escape("unsupported operand type(s) for +: 'int' and 'str'")