Partly solve pandas-dev#23558

Author: h-vetinari

pandas/_libs/lib.pyx

@@ -2258,6 +2258,8 @@ def tuples_to_object_array(ndarray[object] tuples):
     result = np.empty((n, k), dtype=object)
     for i in range(n):
         tup = tuples[i]
+        if checknull(tup):
+            continue
         for j in range(k):
             result[i, j] = tup[j]
 
@@ -2274,6 +2276,8 @@ def to_object_array_tuples(rows: list):
 
     k = 0
     for i in range(n):
+        if checknull(rows[i]):
+            continue
         tmp = len(rows[i])
         if tmp > k:
             k = tmp
@@ -2283,11 +2287,15 @@ def to_object_array_tuples(rows: list):
     try:
         for i in range(n):
             row = rows[i]
+            if checknull(row):
+                continue
             for j in range(len(row)):
                 result[i, j] = row[j]
     except Exception:
         # upcast any subclasses to tuple
         for i in range(n):
+            if checknull(rows[i]):
+                continue
             row = tuple(rows[i])
             for j in range(len(row)):
                 result[i, j] = row[j]

pandas/tests/test_strings.py

@@ -236,8 +236,8 @@ def test_api_per_method(self, box, dtype,
 
         # TODO: get rid of these xfails
         if (method_name in ['partition', 'rpartition'] and box == Index
-                and inferred_dtype != 'bytes'):
-            pytest.xfail(reason='Method not nan-safe on Index; see GH 23558')
+                and inferred_dtype == 'empty'):
+            pytest.xfail(reason='Method cannot deal with empty Index')
         if (method_name == 'get_dummies' and box == Index
                 and inferred_dtype == 'empty' and (dtype == object
                                                    or values.size == 0)):