DOC: add deprecated to docstring of Series.data/itemsize/strides/flags/base (#26132)

Author: jorisvandenbossche

pandas/core/base.py

@@ -703,6 +703,8 @@ def item(self):
     def data(self):
         """
         Return the data pointer of the underlying data.
+
+        .. deprecated:: 0.23.0
         """
         warnings.warn("{obj}.data is deprecated and will be removed "
                       "in a future version".format(obj=type(self).__name__),
@@ -713,6 +715,8 @@ def data(self):
     def itemsize(self):
         """
         Return the size of the dtype of the item of the underlying data.
+
+        .. deprecated:: 0.23.0
         """
         warnings.warn("{obj}.itemsize is deprecated and will be removed "
                       "in a future version".format(obj=type(self).__name__),
@@ -730,6 +734,8 @@ def nbytes(self):
     def strides(self):
         """
         Return the strides of the underlying data.
+
+        .. deprecated:: 0.23.0
         """
         warnings.warn("{obj}.strides is deprecated and will be removed "
                       "in a future version".format(obj=type(self).__name__),
@@ -747,6 +753,8 @@ def size(self):
     def flags(self):
         """
         Return the ndarray.flags for the underlying data.
+
+        .. deprecated:: 0.23.0
         """
         warnings.warn("{obj}.flags is deprecated and will be removed "
                       "in a future version".format(obj=type(self).__name__),
@@ -757,6 +765,8 @@ def flags(self):
     def base(self):
         """
         Return the base object if the memory of the underlying data is shared.
+
+        .. deprecated:: 0.23.0
         """
         warnings.warn("{obj}.base is deprecated and will be removed "
                       "in a future version".format(obj=type(self).__name__),