Backport PR #35522: BUG: Fix assert_equal when check_exact=True for n…

…on-numeric dtypes #3… (#35652)

Co-authored-by: Isaac Virshup <ivirshup@gmail.com>

doc/source/whatsnew/v1.1.1.rst

@@ -17,6 +17,7 @@ Fixed regressions
 
 - Fixed regression where :meth:`DataFrame.to_numpy` would raise a ``RuntimeError`` for mixed dtypes when converting to ``str`` (:issue:`35455`)
 - Fixed regression where :func:`read_csv` would raise a ``ValueError`` when ``pandas.options.mode.use_inf_as_na`` was set to ``True`` (:issue:`35493`).
+- Fixed regression where :func:`pandas.testing.assert_series_equal` would raise an error when non-numeric dtypes were passed with ``check_exact=True`` (:issue:`35446`)
 - Fixed regression in :class:`pandas.core.groupby.RollingGroupby` where column selection was ignored (:issue:`35486`)
 - Fixed regression in :meth:`DataFrame.shift` with ``axis=1`` and heterogeneous dtypes (:issue:`35488`)
 - Fixed regression in ``.groupby(..).rolling(..)`` where a segfault would occur with ``center=True`` and an odd number of values (:issue:`35552`)

pandas/_testing.py

@@ -1339,10 +1339,8 @@ def assert_series_equal(
         else:
             assert_attr_equal("dtype", left, right, obj=f"Attributes of {obj}")
 
-    if check_exact:
-        if not is_numeric_dtype(left.dtype):
-            raise AssertionError("check_exact may only be used with numeric Series")
-
+    if check_exact and is_numeric_dtype(left.dtype) and is_numeric_dtype(right.dtype):
+        # Only check exact if dtype is numeric
         assert_numpy_array_equal(
             left._values,
             right._values,

pandas/tests/util/test_assert_series_equal.py

@@ -281,3 +281,18 @@ class MySeries(Series):
 
     with pytest.raises(AssertionError, match="Series classes are different"):
         tm.assert_series_equal(s3, s1, check_series_type=True)
+
+
+def test_series_equal_exact_for_nonnumeric():
+    # https://github.com/pandas-dev/pandas/issues/35446
+    s1 = Series(["a", "b"])
+    s2 = Series(["a", "b"])
+    s3 = Series(["b", "a"])
+
+    tm.assert_series_equal(s1, s2, check_exact=True)
+    tm.assert_series_equal(s2, s1, check_exact=True)
+
+    with pytest.raises(AssertionError):
+        tm.assert_series_equal(s1, s3, check_exact=True)
+    with pytest.raises(AssertionError):
+        tm.assert_series_equal(s3, s1, check_exact=True)