use instancecheck. Modify SparseArray for 3.6 to use metaclass pattern

Author: Dr-Irv

pandas/__init__.py

@@ -304,41 +304,53 @@ class __Datetime(type):
         datetime = dt
 
         def __getattr__(cls, item):
-            import warnings
-
-            warnings.warn(
-                "The pandas.datetime class is deprecated "
-                "and will be removed from pandas in a future version. "
-                "Import from datetime instead.",
-                FutureWarning,
-                stacklevel=2,
-            )
+            cls.emitWarning()
 
             try:
                 return getattr(cls.datetime, item)
             except AttributeError:
                 raise AttributeError(f"module datetime has no attribute {item}")
 
+        def __instancecheck__(cls, other):
+            if isinstance(other, cls.datetime):
+                return True
+            else:
+                return False
+
     class __DatetimeSub(metaclass=__Datetime):
-        def __new__(cls, *args, **kwargs):
+        def emitWarning():
             import warnings
 
             warnings.warn(
                 "The pandas.datetime class is deprecated "
                 "and will be removed from pandas in a future version. "
                 "Import from datetime instead.",
                 FutureWarning,
-                stacklevel=2,
+                stacklevel=3,
             )
 
+        def __new__(cls, *args, **kwargs):
+            cls.emitWarning()
             from datetime import datetime as dt
 
             return dt(*args, **kwargs)
 
     datetime = __DatetimeSub
 
-    class __SparseArray(pandas.core.arrays.sparse.SparseArray):
-        def __warnSparseArray(self):
+    class __SparseArray(type):
+
+        from pandas.core.arrays.sparse import SparseArray as sa
+
+        SparseArray = sa
+
+        def __instancecheck__(cls, other):
+            if isinstance(other, cls.SparseArray):
+                return True
+            else:
+                return False
+
+    class __SparseArraySub(metaclass=__SparseArray):
+        def emitWarning():
             import warnings
 
             warnings.warn(
@@ -349,23 +361,14 @@ def __warnSparseArray(self):
                 stacklevel=3,
             )
 
-        def __init__(
-            self,
-            data,
-            sparse_index=None,
-            index=None,
-            fill_value=None,
-            kind="integer",
-            dtype=None,
-            copy=False,
-        ):
-            self.__warnSparseArray()
-            super().__init__(data, sparse_index, index, fill_value, kind, dtype, copy)
-
-        def __getattr__(self, name):
-            return super().__getattribute__(name)
-
-    SparseArray = __SparseArray
+        def __new__(cls, *args, **kwargs):
+            cls.emitWarning()
+            from pandas.core.arrays.sparse import SparseArray as sa
+
+            return sa(*args, **kwargs)
+
+    SparseArray = __SparseArraySub
+
 
 # module level doc-string
 __doc__ = """

pandas/tests/api/test_api.py

@@ -235,17 +235,14 @@ def test_depr(self):
         )
         for depr in deprecated_list:
             with tm.assert_produces_warning(FutureWarning):
-                if compat.PY37:
-                    getattr(pd, depr)
-                elif depr == "datetime":
-                    deprecated = getattr(pd, "__Datetime")
-                    deprecated.__getattr__(deprecated, dir(pd.datetime.datetime)[-1])
-                elif depr == "SparseArray":
-                    deprecated = getattr(pd, depr)
-                    deprecated([])
-                else:
-                    deprecated = getattr(pd, depr)
-                    deprecated.__getattr__(dir(deprecated)[-1])
+                deprecated = getattr(pd, depr)
+                if not compat.PY37:
+                    if depr == "datetime":
+                        deprecated.__getattr__(dir(pd.datetime.datetime)[-1])
+                    elif depr == "SparseArray":
+                        deprecated([])
+                    else:
+                        deprecated.__getattr__(dir(deprecated)[-1])
 
 
 def test_datetime():
@@ -256,6 +253,16 @@ def test_datetime():
         warnings.simplefilter("ignore", FutureWarning)
         assert datetime(2015, 1, 2, 0, 0) == pd.datetime(2015, 1, 2, 0, 0)
 
+        assert isinstance(pd.datetime(2015, 1, 2, 0, 0), pd.datetime)
+
+
+def test_sparsearray():
+    import warnings
+
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore", FutureWarning)
+        assert isinstance(pd.array([1, 2, 3], dtype="Sparse"), pd.SparseArray)
+
 
 def test_np():
     import numpy as np