REGR: MultiIndex.isin raising TypeError for generator

doc/source/whatsnew/v2.0.1.rst

@@ -16,6 +16,7 @@ Fixed regressions
 - Fixed regression for subclassed Series when constructing from a dictionary (:issue:`52445`)
 - Fixed regression in :meth:`Series.describe` showing ``RuntimeWarning`` for extension dtype :class:`Series` with one element (:issue:`52515`)
 - Fixed regression in :meth:`DataFrame.sort_values` not resetting index when :class:`DataFrame` is already sorted and ``ignore_index=True`` (:issue:`52553`)
+- Fixed regression in :meth:`MultiIndex.isin` raising ``TypeError`` for ``Generator`` (:issue:`52568`)
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_201.bug_fixes:

pandas/core/indexes/multi.py

@@ -7,6 +7,7 @@
     Any,
     Callable,
     Collection,
+    Generator,
     Hashable,
     Iterable,
     List,
@@ -3772,6 +3773,9 @@ def delete(self, loc) -> MultiIndex:
 
     @doc(Index.isin)
     def isin(self, values, level=None) -> npt.NDArray[np.bool_]:
+        if isinstance(values, Generator):
+            values = list(values)
+
         if level is None:
             if len(values) == 0:
                 return np.zeros((len(self),), dtype=np.bool_)

pandas/tests/indexes/multi/test_isin.py

@@ -93,3 +93,11 @@ def test_isin_empty():
     result = midx.isin([])
     expected = np.array([False, False])
     tm.assert_numpy_array_equal(result, expected)
+
+
+def test_isin_generator():
+    # GH#52568
+    midx = MultiIndex.from_tuples([(1, 2)])
+    result = midx.isin(x for x in [(1, 2)])
+    expected = np.array([True])
+    tm.assert_numpy_array_equal(result, expected)