DEPR/CLN: Remove pd.rolling_*, pd.expanding* and pd.ewm* (pandas-dev#18723)

* remove pd.running_*, pd.expanding_* and pd.ewm* and related code

* added test_expanding_func and test_expanding_apply

* recreate _check_ndarray inline in _check_moment_func

Author: topper-123

doc/source/computation.rst

@@ -209,19 +209,12 @@ Window Functions
 
 .. currentmodule:: pandas.core.window
 
-.. warning::
-
-   Prior to version 0.18.0, ``pd.rolling_*``, ``pd.expanding_*``, and ``pd.ewm*`` were module level
-   functions and are now deprecated. These are replaced by using the :class:`~pandas.core.window.Rolling`, :class:`~pandas.core.window.Expanding` and :class:`~pandas.core.window.EWM`. objects and a corresponding method call.
-
-   The deprecation warning will show the new syntax, see an example :ref:`here <whatsnew_0180.window_deprecations>`.
-
-For working with data, a number of windows functions are provided for
+For working with data, a number of window functions are provided for
 computing common *window* or *rolling* statistics. Among these are count, sum,
 mean, median, correlation, variance, covariance, standard deviation, skewness,
 and kurtosis.
 
-Starting in version 0.18.1, the ``rolling()`` and ``expanding()``
+The ``rolling()`` and ``expanding()``
 functions can be used directly from DataFrameGroupBy objects,
 see the :ref:`groupby docs <groupby.transform.window_resample>`.
 

doc/source/whatsnew/v0.23.0.txt

@@ -361,6 +361,8 @@ Removal of prior version deprecations/changes
 - The ``labels`` attribute of the ``Categorical`` class has been removed in favor of :attribute:`Categorical.codes` (:issue:`7768`)
 - The ``flavor`` parameter have been removed from func:`to_sql` method (:issue:`13611`)
 - The modules `pandas.tools.hashing` and `pandas.util.hashing` have been removed (:issue:`16223`)
+- The top-level functions ``pd.rolling_*``, ``pd.expanding_*`` and ``pd.ewm*`` have been removed (Deprecated since v0.18).
+  Instead, use the DataFrame/Series methods :attr:`~DataFrame.rolling`, :attr:`~DataFrame.expanding` and :attr:`~DataFrame.ewm` (:issue:`18723`)
 
 .. _whatsnew_0230.performance:
 

pandas/__init__.py

@@ -41,7 +41,6 @@
 
 from pandas.core.api import *
 from pandas.core.sparse.api import *
-from pandas.stats.api import *
 from pandas.tseries.api import *
 from pandas.core.computation.api import *
 from pandas.core.reshape.api import *