DEPR: add deprecation warning for com.array_equivalent (#14567)

pandas.core.common.array_equivalent was removed without deprecation warning.
This commits adds it back to the core.common namespace with deprecation warning

Author: jorisvandenbossche

doc/source/whatsnew/v0.19.1.txt

@@ -34,7 +34,7 @@ Bug Fixes
 ~~~~~~~~~
 
 - Compat with Cython 0.25 for building (:issue:`14496`)
-
+- Added back ``pandas.core.common.array_equivalent`` with a deprecation warning (:issue:`14555`).
 
 - Bug in ``pd.read_csv`` for the C engine in which quotation marks were improperly parsed in skipped rows (:issue:`14459`)
 - Bug in ``pd.read_csv`` for Python 2.x in which Unicode quote characters were no longer being respected (:issue:`14477`)

pandas/api/tests/test_api.py

@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
 
+import numpy as np
+
 import pandas as pd
 from pandas.core import common as com
 from pandas import api
@@ -184,6 +186,11 @@ def test_deprecation_core_common(self):
         for t in self.allowed:
             self.check_deprecation(getattr(com, t), getattr(types, t))
 
+    def test_deprecation_core_common_array_equivalent(self):
+
+        with tm.assert_produces_warning(DeprecationWarning):
+            com.array_equivalent(np.array([1, 2]), np.array([1, 2]))
+
     def test_deprecation_core_common_moved(self):
 
         # these are in pandas.types.common

pandas/core/common.py

@@ -64,6 +64,15 @@ def wrapper(*args, **kwargs):
     setattr(m, t, outer(t))
 
 
+# deprecate array_equivalent
+
+def array_equivalent(*args, **kwargs):
+    warnings.warn("'pandas.core.common.array_equivalent' is deprecated and "
+                  "is no longer public API", DeprecationWarning, stacklevel=2)
+    from pandas.types import missing
+    return missing.array_equivalent(*args, **kwargs)
+
+
 class PandasError(Exception):
     pass