DEPR: deprecate .asobject property (#18572)

asv_bench/benchmarks/index_object.py

@@ -12,7 +12,7 @@ def setup(self):
         if (self.rng.dtype == object):
             self.idx_rng = self.rng.view(Index)
         else:
-            self.idx_rng = self.rng.asobject
+            self.idx_rng = self.rng.astype(object)
         self.idx_rng2 = self.idx_rng[:(-1)]
 
         # other datetime

doc/source/whatsnew/v0.22.0.txt

@@ -124,7 +124,7 @@ Deprecations
 
 - ``Series.from_array`` and ``SparseSeries.from_array`` are deprecated. Use the normal constructor ``Series(..)`` and ``SparseSeries(..)`` instead (:issue:`18213`).
 - ``DataFrame.as_matrix`` is deprecated. Use ``DataFrame.values`` instead (:issue:`18458`).
--
+- ``Series.asobject``, ``DatetimeIndex.asobject``, ``PeriodIndex.asobject`` and ``TimeDeltaIndex.asobject`` have been deprecated. Use '.astype(object)' instead (:issue:`18572`)
 
 .. _whatsnew_0220.prior_deprecations:
 

pandas/_libs/algos_common_helper.pxi.in

@@ -552,8 +552,8 @@ cpdef ensure_object(object arr):
             return arr
         else:
             return arr.astype(np.object_)
-    elif hasattr(arr, 'asobject'):
-        return arr.asobject
+    elif hasattr(arr, '_box_values_as_index'):
+        return arr._box_values_as_index()
     else:
         return np.array(arr, dtype=np.object_)
 

pandas/core/accessor.py

@@ -10,7 +10,7 @@
 
 class DirNamesMixin(object):
     _accessors = frozenset([])
-    _deprecations = frozenset([])
+    _deprecations = frozenset(['asobject'])
 
     def _dir_deletions(self):
         """ delete unwanted __dir__ for this object """

pandas/core/algorithms.py

@@ -369,7 +369,7 @@ def unique(values):
         # to return an object array of tz-aware Timestamps
 
         # TODO: it must return DatetimeArray with tz in pandas 2.0
-        uniques = uniques.asobject.values
+        uniques = uniques.astype(object).values
 
     return uniques
 

pandas/core/dtypes/concat.py

@@ -401,7 +401,7 @@ def convert_to_pydatetime(x, axis):
         # if dtype is of datetimetz or timezone
         if x.dtype.kind == _NS_DTYPE.kind:
             if getattr(x, 'tz', None) is not None:
-                x = x.asobject.values
+                x = x.astype(object).values
             else:
                 shape = x.shape
                 x = tslib.ints_to_pydatetime(x.view(np.int64).ravel(),
@@ -479,7 +479,7 @@ def _concat_index_asobject(to_concat, name=None):
     """
 
     klasses = ABCDatetimeIndex, ABCTimedeltaIndex, ABCPeriodIndex
-    to_concat = [x.asobject if isinstance(x, klasses) else x
+    to_concat = [x.astype(object) if isinstance(x, klasses) else x
                  for x in to_concat]
 
     from pandas import Index

pandas/core/frame.py

@@ -3330,7 +3330,7 @@ class    max    type
 
         def _maybe_casted_values(index, labels=None):
             if isinstance(index, PeriodIndex):
-                values = index.asobject.values
+                values = index.astype(object).values
             elif isinstance(index, DatetimeIndex) and index.tz is not None:
                 values = index
             else:
@@ -5077,7 +5077,7 @@ def applymap(self, func):
         def infer(x):
             if x.empty:
                 return lib.map_infer(x, func)
-            return lib.map_infer(x.asobject, func)
+            return lib.map_infer(x.astype(object).values, func)
 
         return self.apply(infer)
 

pandas/core/indexes/datetimelike.py

@@ -242,6 +242,13 @@ def _box_values(self, values):
         """
         return lib.map_infer(values, self._box_func)
 
+    def _box_values_as_index(self):
+        """
+        return object Index which contains boxed values
+        """
+        from pandas.core.index import Index
+        return Index(self._box_values(self.asi8), name=self.name, dtype=object)
+
     def _format_with_header(self, header, **kwargs):
         return header + list(self._format_native_types(**kwargs))
 
@@ -360,7 +367,7 @@ def map(self, f):
                 raise TypeError('The map function must return an Index object')
             return result
         except Exception:
-            return self.asobject.map(f)
+            return self.astype(object).map(f)
 
     def sort_values(self, return_indexer=False, ascending=True):
         """
@@ -424,13 +431,15 @@ def _isnan(self):
 
     @property
     def asobject(self):
-        """
+        """DEPRECATED: Use ``astype(object)`` instead.
+
         return object Index which contains boxed values
 
         *this is an internal non-public method*
         """
-        from pandas.core.index import Index
-        return Index(self._box_values(self.asi8), name=self.name, dtype=object)
+        warnings.warn("'asobject' is deprecated. Use 'astype(object)'"
+                      " instead", FutureWarning, stacklevel=2)
+        return self.astype(object)
 
     def _convert_tolerance(self, tolerance, target):
         tolerance = np.asarray(to_timedelta(tolerance, box=False))
@@ -468,7 +477,7 @@ def tolist(self):
         """
         return a list of the underlying data
         """
-        return list(self.asobject)
+        return list(self.astype(object))
 
     def min(self, axis=None, *args, **kwargs):
         """
@@ -746,7 +755,7 @@ def isin(self, values):
             try:
                 values = type(self)(values)
             except ValueError:
-                return self.asobject.isin(values)
+                return self.astype(object).isin(values)
 
         return algorithms.isin(self.asi8, values.asi8)
 

pandas/core/indexes/datetimes.py

@@ -907,7 +907,7 @@ def to_datetime(self, dayfirst=False):
     def astype(self, dtype, copy=True):
         dtype = pandas_dtype(dtype)
         if is_object_dtype(dtype):
-            return self.asobject
+            return self._box_values_as_index()
         elif is_integer_dtype(dtype):
             return Index(self.values.astype('i8', copy=copy), name=self.name,
                          dtype='i8')
@@ -1679,7 +1679,7 @@ def time(self):
         Returns numpy array of datetime.time. The time part of the Timestamps.
         """
         return self._maybe_mask_results(libalgos.arrmap_object(
-            self.asobject.values,
+            self.astype(object).values,
             lambda x: np.nan if x is libts.NaT else x.time()))
 
     @property
@@ -1789,7 +1789,7 @@ def insert(self, loc, item):
 
             # fall back to object index
             if isinstance(item, compat.string_types):
-                return self.asobject.insert(loc, item)
+                return self.astype(object).insert(loc, item)
             raise TypeError(
                 "cannot insert DatetimeIndex with incompatible label")
 

pandas/core/indexes/period.py

@@ -418,7 +418,7 @@ def _int64index(self):
 
     @property
     def values(self):
-        return self.asobject.values
+        return self.astype(object).values
 
     @property
     def _values(self):
@@ -428,7 +428,7 @@ def __array__(self, dtype=None):
         if is_integer_dtype(dtype):
             return self.asi8
         else:
-            return self.asobject.values
+            return self.astype(object).values
 
     def __array_wrap__(self, result, context=None):
         """
@@ -476,7 +476,7 @@ def _to_embed(self, keep_tz=False, dtype=None):
         if dtype is not None:
             return self.astype(dtype)._to_embed(keep_tz=keep_tz)
 
-        return self.asobject.values
+        return self.astype(object).values
 
     @property
     def _formatter_func(self):
@@ -506,7 +506,7 @@ def asof_locs(self, where, mask):
     def astype(self, dtype, copy=True, how='start'):
         dtype = pandas_dtype(dtype)
         if is_object_dtype(dtype):
-            return self.asobject
+            return self._box_values_as_index()
         elif is_integer_dtype(dtype):
             if copy:
                 return self._int64index.copy()
@@ -656,7 +656,7 @@ def end_time(self):
 
     def _mpl_repr(self):
         # how to represent ourselves to matplotlib
-        return self.asobject.values
+        return self.astype(object).values
 
     def to_timestamp(self, freq=None, how='start'):
         """
@@ -971,7 +971,7 @@ def _convert_tolerance(self, tolerance, target):
 
     def insert(self, loc, item):
         if not isinstance(item, Period) or self.freq != item.freq:
-            return self.asobject.insert(loc, item)
+            return self.astype(object).insert(loc, item)
 
         idx = np.concatenate((self[:loc].asi8, np.array([item.ordinal]),
                               self[loc:].asi8))
@@ -1018,7 +1018,7 @@ def _apply_meta(self, rawarr):
     def _format_native_types(self, na_rep=u('NaT'), date_format=None,
                              **kwargs):
 
-        values = self.asobject.values
+        values = self.astype(object).values
 
         if date_format:
             formatter = lambda dt: dt.strftime(date_format)

pandas/core/indexes/timedeltas.py

@@ -482,7 +482,7 @@ def astype(self, dtype, copy=True):
         dtype = np.dtype(dtype)
 
         if is_object_dtype(dtype):
-            return self.asobject
+            return self._box_values_as_index()
         elif is_timedelta64_ns_dtype(dtype):
             if copy is True:
                 return self.copy()
@@ -883,7 +883,7 @@ def insert(self, loc, item):
 
             # fall back to object index
             if isinstance(item, compat.string_types):
-                return self.asobject.insert(loc, item)
+                return self.astype(object).insert(loc, item)
             raise TypeError(
                 "cannot insert TimedeltaIndex with incompatible label")
 

pandas/core/indexing.py

@@ -405,7 +405,8 @@ def _setitem_with_indexer(self, indexer, value):
                             new_values = np.concatenate([self.obj._values,
                                                          new_values])
                         except TypeError:
-                            new_values = np.concatenate([self.obj.asobject,
+                            as_obj = self.obj.astype(object)
+                            new_values = np.concatenate([as_obj,
                                                          new_values])
                     self.obj._data = self.obj._constructor(
                         new_values, index=new_index, name=self.obj.name)._data

pandas/core/internals.py

@@ -2191,7 +2191,7 @@ def _try_coerce_args(self, values, other):
 
         if isinstance(other, ABCDatetimeIndex):
             # to store DatetimeTZBlock as object
-            other = other.asobject.values
+            other = other.astype(object).values
 
         return values, False, other, False
 

pandas/core/ops.py

@@ -850,7 +850,7 @@ def wrapper(self, other, axis=None):
                 # tested in test_nat_comparisons
                 # (pandas.tests.series.test_operators.TestSeriesOperators)
                 return self._constructor(na_op(self.values,
-                                               other.asobject.values),
+                                               other.astype(object).values),
                                          index=self.index)
 
             return self._constructor(na_op(self.values, np.asarray(other)),

pandas/core/series.py

@@ -149,7 +149,8 @@ class Series(base.IndexOpsMixin, generic.NDFrame):
     _metadata = ['name']
     _accessors = frozenset(['dt', 'cat', 'str'])
     _deprecations = generic.NDFrame._deprecations | frozenset(
-        ['sortlevel', 'reshape', 'get_value', 'set_value', 'from_csv'])
+        ['asobject', 'sortlevel', 'reshape', 'get_value', 'set_value',
+         'from_csv'])
     _allow_index_ops = True
 
     def __init__(self, data=None, index=None, dtype=None, name=None,
@@ -449,12 +450,15 @@ def get_values(self):
 
     @property
     def asobject(self):
-        """
+        """DEPRECATED: Use ``astype(object)`` instead.
+
         return object Series which contains boxed values
 
         *this is an internal non-public method*
         """
-        return self._data.asobject
+        warnings.warn("'asobject' is deprecated. Use 'astype(object)'"
+                      " instead", FutureWarning, stacklevel=2)
+        return self.astype(object).values
 
     # ops
     def ravel(self, order='C'):
@@ -1322,7 +1326,7 @@ def unique(self):
             # to return an object array of tz-aware Timestamps
 
             # TODO: it must return DatetimeArray with tz in pandas 2.0
-            result = result.asobject.values
+            result = result.astype(object).values
 
         return result
 
@@ -2549,7 +2553,7 @@ def apply(self, func, convert_dtype=True, args=(), **kwds):
             if is_extension_type(self.dtype):
                 mapped = self._values.map(f)
             else:
-                values = self.asobject
+                values = self.astype(object).values
                 mapped = lib.map_infer(values, f, convert=convert_dtype)
 
         if len(mapped) and isinstance(mapped[0], Series):
@@ -3125,7 +3129,7 @@ def _sanitize_index(data, index, copy=False):
     if isinstance(data, ABCIndexClass) and not copy:
         pass
     elif isinstance(data, PeriodIndex):
-        data = data.asobject
+        data = data.astype(object).values
     elif isinstance(data, DatetimeIndex):
         data = data._to_embed(keep_tz=True)
     elif isinstance(data, np.ndarray):

pandas/io/formats/format.py

@@ -2231,7 +2231,7 @@ class Datetime64TZFormatter(Datetime64Formatter):
     def _format_strings(self):
         """ we by definition have a TZ """
 
-        values = self.values.asobject
+        values = self.values.astype(object)
         is_dates_only = _is_dates_only(values)
         formatter = (self.formatter or
                      _get_format_datetime64(is_dates_only,

pandas/plotting/_converter.py

@@ -363,7 +363,8 @@ def __call__(self):
         tz = self.tz.tzname(None)
         st = _from_ordinal(dates.date2num(dmin))  # strip tz
         ed = _from_ordinal(dates.date2num(dmax))
-        all_dates = date_range(start=st, end=ed, freq=freq, tz=tz).asobject
+        all_dates = date_range(start=st, end=ed,
+                               freq=freq, tz=tz).astype(object)
 
         try:
             if len(all_dates) > 0:

pandas/tests/frame/test_constructors.py

@@ -501,8 +501,8 @@ def test_constructor_period(self):
         assert df['b'].dtype == 'object'
 
         # list of periods
-        df = pd.DataFrame({'a': a.asobject.tolist(),
-                           'b': b.asobject.tolist()})
+        df = pd.DataFrame({'a': a.astype(object).tolist(),
+                           'b': b.astype(object).tolist()})
         assert df['a'].dtype == 'object'
         assert df['b'].dtype == 'object'
 

pandas/tests/indexes/datetimelike.py

@@ -76,3 +76,10 @@ def test_map_dictlike(self, mapper):
         expected = pd.Index([np.nan] * len(self.index))
         result = self.index.map(mapper([], []))
         tm.assert_index_equal(result, expected)
+
+    def test_asobject_deprecated(self):
+        # GH18572
+        d = self.create_index()
+        with tm.assert_produces_warning(FutureWarning):
+            i = d.asobject
+        assert isinstance(i, pd.Index)