BUG: tuple-of-tuples indexing results in NumPy VisibleDeprecationWarning

pandas/core/common.py

@@ -138,9 +138,12 @@ def is_bool_indexer(key: Any) -> bool:
             return True
     elif isinstance(key, list):
         try:
-            arr = np.asarray(key)
+            # https://github.com/pandas-dev/pandas/issues/35434
+            with warnings.catch_warnings():
+                warnings.simplefilter("ignore", category=np.VisibleDeprecationWarning)
+                arr = np.asarray(key)
             return arr.dtype == np.bool_ and len(arr) == len(key)
-        except TypeError:  # pragma: no cover
+        except (TypeError, ValueError):  # pragma: no cover
             return False
 
     return False
@@ -225,7 +228,15 @@ def asarray_tuplesafe(values, dtype=None):
     if isinstance(values, list) and dtype in [np.object_, object]:
         return construct_1d_object_array_from_listlike(values)
 
-    result = np.asarray(values, dtype=dtype)
+    try:
+        # https://github.com/pandas-dev/pandas/issues/35434
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", category=np.VisibleDeprecationWarning)
+            result = np.asarray(values, dtype=dtype)
+    except ValueError:
+        # we get here with a list-like of nested values if dtype=None
+        # for numpy < 1.18
+        return construct_1d_object_array_from_listlike(values)
 
     if issubclass(result.dtype.type, str):
         result = np.asarray(values, dtype=object)

pandas/core/indexers.py

@@ -17,6 +17,41 @@
 )
 from pandas.core.dtypes.generic import ABCIndexClass, ABCSeries
 
+from pandas.core.dtypes.common import is_scalar, is_iterator
+import pandas.core.common as com
+
+
+class Indexer:
+    _is_iterator = None
+    _is_bool_indexer = None
+
+    def __init__(self, key):
+        if isinstance(key, (list, tuple)):
+            key = unpack_1tuple(key)
+        self.key = key
+
+    @property
+    def is_scalar(self):
+        return is_scalar(self.key)
+
+    @property
+    def is_bool_indexer(self):
+        is_bool_indexer = self._is_bool_indexer
+        if is_bool_indexer is not None:
+            return is_bool_indexer
+
+        key = self.key
+        if self._is_iterator is None:
+            if is_iterator(key):
+                key = list(key)
+                self.key = key
+            self._is_iterator = False
+
+        is_bool_indexer = com.is_bool_indexer(key)
+        self._is_bool_indexer = is_bool_indexer
+        return is_bool_indexer
+
+
 # -----------------------------------------------------------
 # Indexer Identification
 

pandas/core/series.py

@@ -50,7 +50,6 @@
     is_dict_like,
     is_extension_array_dtype,
     is_integer,
-    is_iterator,
     is_list_like,
     is_object_dtype,
     is_scalar,
@@ -78,7 +77,7 @@
     sanitize_array,
 )
 from pandas.core.generic import NDFrame
-from pandas.core.indexers import deprecate_ndim_indexing, unpack_1tuple
+from pandas.core.indexers import deprecate_ndim_indexing, unpack_1tuple, Indexer
 from pandas.core.indexes.accessors import CombinedDatetimelikeProperties
 from pandas.core.indexes.api import Float64Index, Index, MultiIndex, ensure_index
 import pandas.core.indexes.base as ibase
@@ -897,17 +896,23 @@ def __getitem__(self, key):
                 #  in the first level of our MultiIndex
                 return self._get_values_tuple(key)
 
-        if is_iterator(key):
-            key = list(key)
+        # if is_iterator(key):
+        #     key = list(key)
+
+        _key = Indexer(key)
 
-        if com.is_bool_indexer(key):
+        if _key.is_bool_indexer:
             key = check_bool_indexer(self.index, key)
             key = np.asarray(key, dtype=bool)
             return self._get_values(key)
 
-        return self._get_with(key)
+        return self._get_with(_key)
 
     def _get_with(self, key):
+        # breakpoint()
+        _key = key
+        key = _key.key
+
         # other: fancy integer or otherwise
         if isinstance(key, slice):
             # _convert_slice_indexer to determine if this slice is positional

pandas/tests/indexing/test_indexing.py

@@ -1110,3 +1110,12 @@ def test_setitem_categorical():
         {"h": pd.Categorical(["m", "n"]).reorder_categories(["n", "m"])}
     )
     tm.assert_frame_equal(df, expected)
+
+
+def test_nested_tuple_no_warning():
+    # https://github.com/pandas-dev/pandas/issues/35434
+    tup = "A", ("B", 2)
+    ser = pd.Series([42], index=[tup])
+    with tm.assert_produces_warning(None):
+        result = ser[[tup]]
+    tm.assert_series_equal(result, ser)