make datetime work with 3.6

Author: Dr-Irv

pandas/__init__.py

@@ -297,13 +297,13 @@ def __getattr__(self, item):
 
     np = __numpy()
 
-    class __Datetime:
-        def __init__(self):
-            from datetime import datetime as dt
+    class __Datetime(type):
 
-            self.datetime = dt
+        from datetime import datetime as dt
 
-        def __getattr__(self, item):
+        datetime = dt
+
+        def __getattr__(cls, item):
             import warnings
 
             warnings.warn(
@@ -315,11 +315,27 @@ def __getattr__(self, item):
             )
 
             try:
-                return getattr(self.datetime, item)
+                return getattr(cls.datetime, item)
             except AttributeError:
                 raise AttributeError(f"module datetime has no attribute {item}")
 
-    datetime = __Datetime()
+    class __DatetimeSub(metaclass=__Datetime):
+        def __new__(cls, *args, **kwargs):
+            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,
+            )
+
+            from datetime import datetime as dt
+
+            return dt(*args, **kwargs)
+
+    datetime = __DatetimeSub
 
     class __SparseArray(pandas.core.arrays.sparse.SparseArray):
         def __warnSparseArray(self):

pandas/tests/api/test_api.py

@@ -239,7 +239,7 @@ def test_depr(self):
                     getattr(pd, depr)
                 elif depr == "datetime":
                     deprecated = getattr(pd, "__Datetime")
-                    deprecated().__getattr__(dir(pd.datetime.datetime)[-1])
+                    deprecated.__getattr__(deprecated, dir(pd.datetime.datetime)[-1])
                 elif depr == "SparseArray":
                     deprecated = getattr(pd, depr)
                     deprecated([])
@@ -252,10 +252,9 @@ def test_datetime():
     from datetime import datetime
     import warnings
 
-    if compat.PY37:
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", FutureWarning)
-            assert datetime(2015, 1, 2, 0, 0) == pd.datetime(2015, 1, 2, 0, 0)
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore", FutureWarning)
+        assert datetime(2015, 1, 2, 0, 0) == pd.datetime(2015, 1, 2, 0, 0)
 
 
 def test_np():