ENH: Add check_like functionality to assert_series_equal (#47248)

* Add check_like functionality to assert_series_equal

* fix code formatting issues

* versionadded and whatsnew

* fix test comment

Author: stevenschaerer

doc/source/whatsnew/v1.5.0.rst

@@ -152,6 +152,7 @@ Other enhancements
 - Added ``numeric_only`` argument to :meth:`Resampler.sum`, :meth:`Resampler.prod`, :meth:`Resampler.min`, :meth:`Resampler.max`, :meth:`Resampler.first`, and :meth:`Resampler.last` (:issue:`46442`)
 - ``times`` argument in :class:`.ExponentialMovingWindow` now accepts ``np.timedelta64`` (:issue:`47003`)
 - :class:`DataError`, :class:`SpecificationError`, :class:`SettingWithCopyError`, and :class:`SettingWithCopyWarning` are now exposed in ``pandas.errors`` (:issue:`27656`)
+- Added ``check_like`` argument to :func:`testing.assert_series_equal` (:issue:`47247`)
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_150.notable_bug_fixes:

pandas/_testing/asserters.py

@@ -879,6 +879,7 @@ def assert_series_equal(
     obj="Series",
     *,
     check_index=True,
+    check_like=False,
 ):
     """
     Check that left and right Series are equal.
@@ -944,6 +945,11 @@ def assert_series_equal(
         Whether to check index equivalence. If False, then compare only values.
 
         .. versionadded:: 1.3.0
+    check_like : bool, default False
+        If True, ignore the order of the index. Must be False if check_index is False.
+        Note: same labels must be with the same data.
+
+        .. versionadded:: 1.5.0
 
     Examples
     --------
@@ -954,6 +960,9 @@ def assert_series_equal(
     """
     __tracebackhide__ = True
 
+    if not check_index and check_like:
+        raise ValueError("check_like must be False if check_index is False")
+
     if check_less_precise is not no_default:
         warnings.warn(
             "The 'check_less_precise' keyword in testing.assert_*_equal "
@@ -988,11 +997,15 @@ def assert_series_equal(
             check_names=check_names,
             check_exact=check_exact,
             check_categorical=check_categorical,
+            check_order=not check_like,
             rtol=rtol,
             atol=atol,
             obj=f"{obj}.index",
         )
 
+    if check_like:
+        left, right = left.reindex_like(right), right
+
     if check_freq and isinstance(left.index, (DatetimeIndex, TimedeltaIndex)):
         lidx = left.index
         ridx = right.index

pandas/tests/util/test_assert_series_equal.py

@@ -158,6 +158,37 @@ def test_series_equal_index_dtype(s1, s2, msg, check_index_type):
         tm.assert_series_equal(s1, s2, **kwargs)
 
 
+@pytest.mark.parametrize("check_like", [True, False])
+def test_series_equal_order_mismatch(check_like):
+    s1 = Series([1, 2, 3], index=["a", "b", "c"])
+    s2 = Series([3, 2, 1], index=["c", "b", "a"])
+
+    if not check_like:  # Do not ignore index ordering.
+        with pytest.raises(AssertionError, match="Series.index are different"):
+            tm.assert_series_equal(s1, s2, check_like=check_like)
+    else:
+        _assert_series_equal_both(s1, s2, check_like=check_like)
+
+
+@pytest.mark.parametrize("check_index", [True, False])
+def test_series_equal_index_mismatch(check_index):
+    s1 = Series([1, 2, 3], index=["a", "b", "c"])
+    s2 = Series([1, 2, 3], index=["c", "b", "a"])
+
+    if check_index:  # Do not ignore index.
+        with pytest.raises(AssertionError, match="Series.index are different"):
+            tm.assert_series_equal(s1, s2, check_index=check_index)
+    else:
+        _assert_series_equal_both(s1, s2, check_index=check_index)
+
+
+def test_series_invalid_param_combination():
+    with pytest.raises(
+        ValueError, match="check_like must be False if check_index is False"
+    ):
+        tm.assert_series_equal(Series(), Series(), check_index=False, check_like=True)
+
+
 def test_series_equal_length_mismatch(rtol):
     msg = """Series are different