From 4bead6f7e3ec0b4aaa47f4b57ee54436594ae877 Mon Sep 17 00:00:00 2001
From: Jeff Reback <jeff@reback.net>
Date: Tue, 18 Jul 2017 07:07:48 -0400
Subject: [PATCH] deprecate isnull/notnull

---
 pandas/core/categorical.py    |  8 ++++----
 pandas/core/dtypes/missing.py | 13 ++++++++++---
 pandas/core/generic.py        |  7 ++++---
 pandas/core/indexes/base.py   |  8 ++++----
 pandas/core/sparse/frame.py   |  6 +++---
 pandas/core/sparse/series.py  |  5 +++--
 pandas/util/__init__.py       |  2 +-
 pandas/util/_decorators.py    | 22 ++++++++++++++++++++--
 8 files changed, 49 insertions(+), 22 deletions(-)

diff --git a/pandas/core/categorical.py b/pandas/core/categorical.py
index 3810455521a65c..79ab25266770a4 100644
--- a/pandas/core/categorical.py
+++ b/pandas/core/categorical.py
@@ -34,8 +34,8 @@
 import pandas.core.common as com
 from pandas.core.missing import interpolate_2d
 from pandas.compat.numpy import function as nv
-from pandas.util._decorators import (Appender, cache_readonly,
-                                     deprecate_kwarg, Substitution)
+from pandas.util._decorators import (
+    Appender, cache_readonly, deprecate_kwarg, deprecate, Substitution)
 
 from pandas.io.formats.terminal import get_terminal_size
 from pandas.util._validators import validate_bool_kwarg
@@ -1179,7 +1179,7 @@ def isna(self):
                 # we only have one NA in categories
                 ret = np.logical_or(ret, self._codes == nan_pos)
         return ret
-    isull = isna
+    isnull = deprecate('isna', isna, klass=DeprecationWarning)
 
     def notna(self):
         """
@@ -1199,7 +1199,7 @@ def notna(self):
 
         """
         return ~self.isna()
-    notnull = notna
+    notnull = deprecate('notna', notna, klass=DeprecationWarning)
 
     def put(self, *args, **kwargs):
         """
diff --git a/pandas/core/dtypes/missing.py b/pandas/core/dtypes/missing.py
index 45b8af6277c4c0..2932218c5dd86b 100644
--- a/pandas/core/dtypes/missing.py
+++ b/pandas/core/dtypes/missing.py
@@ -1,6 +1,7 @@
 """
 missing types & inference
 """
+import warnings
 import numpy as np
 from pandas._libs import lib
 from pandas._libs.tslib import NaT, iNaT
@@ -44,7 +45,10 @@ def isna(obj):
     return _isna(obj)
 
 
-isnull = isna
+def isnull(obj):
+    warnings.warn("isnull is deprecated. Use isna instead",
+                  DeprecationWarning, stacklevel=2)
+    return isna(obj)
 
 
 def _isna_new(obj):
@@ -213,7 +217,10 @@ def notna(obj):
     return ~res
 
 
-notnull = notna
+def notnull(obj):
+    warnings.warn("notnull is deprecated. Use notna instead",
+                  DeprecationWarning, stacklevel=2)
+    return notna(obj)
 
 
 def is_null_datelike_scalar(other):
@@ -406,4 +413,4 @@ def remove_na_arraylike(arr):
     """
     Return array-like containing only true/non-NaN values, possibly empty.
     """
-    return arr[notnull(lib.values_from_object(arr))]
+    return arr[notna(lib.values_from_object(arr))]
diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index 36ecf82ca4b1e7..b9934875a1e443 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -54,7 +54,8 @@
                            isidentifier, set_function_name, cPickle as pkl)
 from pandas.core.ops import _align_method_FRAME
 import pandas.core.nanops as nanops
-from pandas.util._decorators import Appender, Substitution, deprecate_kwarg
+from pandas.util._decorators import (Appender, Substitution,
+                                     deprecate, deprecate_kwarg)
 from pandas.util._validators import validate_bool_kwarg
 from pandas.core import config
 
@@ -4412,7 +4413,7 @@ def asof(self, where, subset=None):
     @Appender(_shared_docs['isna'])
     def isna(self):
         return isna(self).__finalize__(self)
-    isnull = isna
+    isnull = deprecate('isna', isna, klass=DeprecationWarning)
 
     _shared_docs['notna'] = """
         Return a boolean same-sized object indicating if the values are
@@ -4426,7 +4427,7 @@ def isna(self):
     @Appender(_shared_docs['notna'])
     def notna(self):
         return notna(self).__finalize__(self)
-    notnull = notna
+    notnull = deprecate('notna', notna, klass=DeprecationWarning)
 
     def _clip_with_scalar(self, lower, upper, inplace=False):
         if ((lower is not None and np.any(isna(lower))) or
diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index a2ee7b9e29a50d..0bbd71642daf39 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -41,8 +41,8 @@
 
 from pandas.core.base import PandasObject, IndexOpsMixin
 import pandas.core.base as base
-from pandas.util._decorators import (Appender, Substitution,
-                                     cache_readonly, deprecate_kwarg)
+from pandas.util._decorators import (
+    Appender, Substitution, cache_readonly, deprecate, deprecate_kwarg)
 from pandas.core.indexes.frozen import FrozenList
 import pandas.core.common as com
 import pandas.core.dtypes.concat as _concat
@@ -1848,7 +1848,7 @@ def isna(self):
         pandas.isna : pandas version
         """
         return self._isnan
-    isnull = isna
+    isnull = deprecate('isna', isna, klass=DeprecationWarning)
 
     def notna(self):
         """
@@ -1865,7 +1865,7 @@ def notna(self):
         pandas.notna : pandas version
         """
         return ~self.isna()
-    notnull = notna
+    notnull = deprecate('notna', notna, klass=DeprecationWarning)
 
     def putmask(self, mask, value):
         """
diff --git a/pandas/core/sparse/frame.py b/pandas/core/sparse/frame.py
index 9f94794b4b317a..5cf0546af2ad17 100644
--- a/pandas/core/sparse/frame.py
+++ b/pandas/core/sparse/frame.py
@@ -26,7 +26,7 @@
 import pandas.core.generic as generic
 from pandas.core.sparse.series import SparseSeries, SparseArray
 from pandas._libs.sparse import BlockIndex, get_blocks
-from pandas.util._decorators import Appender
+from pandas.util._decorators import Appender, deprecate
 import pandas.core.ops as ops
 
 
@@ -785,12 +785,12 @@ def cumsum(self, axis=0, *args, **kwargs):
     @Appender(generic._shared_docs['isna'])
     def isna(self):
         return self._apply_columns(lambda x: x.isna())
-    isnull = isna
+    isnull = deprecate('isna', isna, klass=DeprecationWarning)
 
     @Appender(generic._shared_docs['notna'])
     def notna(self):
         return self._apply_columns(lambda x: x.notna())
-    notnull = notna
+    notnull = deprecate('notna', notna, klass=DeprecationWarning)
 
     def apply(self, func, axis=0, broadcast=False, reduce=False):
         """
diff --git a/pandas/core/sparse/series.py b/pandas/core/sparse/series.py
index 2c46624c025a77..a1d82f4c7931bb 100644
--- a/pandas/core/sparse/series.py
+++ b/pandas/core/sparse/series.py
@@ -28,6 +28,7 @@
     _make_index)
 from pandas._libs.sparse import BlockIndex, IntIndex
 import pandas._libs.sparse as splib
+from pandas.util._decorators import deprecate
 
 from pandas.core.sparse.scipy_sparse import (
     _sparse_series_to_coo,
@@ -648,7 +649,7 @@ def isna(self):
                           sparse_index=self.values.sp_index,
                           fill_value=isna(self.fill_value))
         return self._constructor(arr, index=self.index).__finalize__(self)
-    isnull = isna
+    isnull = deprecate('isna', isna, klass=DeprecationWarning)
 
     @Appender(generic._shared_docs['notna'])
     def notna(self):
@@ -656,7 +657,7 @@ def notna(self):
                           sparse_index=self.values.sp_index,
                           fill_value=notna(self.fill_value))
         return self._constructor(arr, index=self.index).__finalize__(self)
-    notnull = notna
+    notnull = deprecate('notna', notna, klass=DeprecationWarning)
 
     def dropna(self, axis=0, inplace=False, **kwargs):
         """
diff --git a/pandas/util/__init__.py b/pandas/util/__init__.py
index e86af930fef7c3..202e58c916e473 100644
--- a/pandas/util/__init__.py
+++ b/pandas/util/__init__.py
@@ -1,2 +1,2 @@
-from pandas.core.util.hashing import hash_pandas_object, hash_array   # noqa
 from pandas.util._decorators import Appender, Substitution, cache_readonly  # noqa
+from pandas.core.util.hashing import hash_pandas_object, hash_array   # noqa
diff --git a/pandas/util/_decorators.py b/pandas/util/_decorators.py
index 772b206f82e699..e406698fafe63a 100644
--- a/pandas/util/_decorators.py
+++ b/pandas/util/_decorators.py
@@ -6,12 +6,30 @@
 from functools import wraps, update_wrapper
 
 
-def deprecate(name, alternative, alt_name=None):
+def deprecate(name, alternative, alt_name=None, klass=None,
+              stacklevel=2):
+    """
+
+    Return a new function that emits a deprecation warning on use
+
+    Parameters
+    ----------
+    name : str
+        Name of function to deprecate
+    alternative : str
+        Name of function to use instead
+    alt_name : str, optional
+        Name to use in preference of alternative.__name__
+    klass : Warning, default FutureWarning
+    stacklevel : int, default 2
+
+    """
     alt_name = alt_name or alternative.__name__
+    klass = klass or FutureWarning
 
     def wrapper(*args, **kwargs):
         warnings.warn("%s is deprecated. Use %s instead" % (name, alt_name),
-                      FutureWarning, stacklevel=2)
+                      klass, stacklevel=stacklevel)
         return alternative(*args, **kwargs)
     return wrapper