changing default to None

doc/source/whatsnew/v0.23.0.txt

@@ -219,7 +219,7 @@ Deprecations
 - ``Series.valid`` is deprecated. Use :meth:`Series.dropna` instead (:issue:`18800`).
 - :func:`read_excel` has deprecated the ``skip_footer`` parameter. Use ``skipfooter`` instead (:issue:`18836`)
 - The ``is_copy`` attribute is deprecated and will be removed in a future version (:issue:`18801`).
-- The ``convert_datetime64`` parameter in :func:`DataFrame.to_records` has been deprecated and the default value is now ``False``. The NumPy bug motivating this parameter has been resolved (:issue:`18160`).
+- The ``convert_datetime64`` parameter in :func:`DataFrame.to_records` has been deprecated and will be removed in a future version. The NumPy bug motivating this parameter has been resolved (:issue:`18160`).
 
 .. _whatsnew_0230.prior_deprecations:
 

pandas/core/frame.py

@@ -1187,7 +1187,7 @@ def from_records(cls, data, index=None, exclude=None, columns=None,
 
         return cls(mgr)
 
-    def to_records(self, index=True, convert_datetime64=False):
+    def to_records(self, index=True, convert_datetime64=None):
         """
         Convert DataFrame to record array. Index will be put in the
         'index' field of the record array if requested
@@ -1196,7 +1196,7 @@ def to_records(self, index=True, convert_datetime64=False):
         ----------
         index : boolean, default True
             Include index in resulting record array, stored in 'index' field
-        convert_datetime64 : boolean, default False
+        convert_datetime64 : boolean, optional
             .. deprecated:: 0.23.0
 
             Whether to convert the index to datetime.datetime if it is a
@@ -1207,7 +1207,7 @@ def to_records(self, index=True, convert_datetime64=False):
         y : recarray
         """
 
-        if convert_datetime64:
+        if convert_datetime64 is not None:
             warnings.warn("The 'convert_datetime64' parameter is "
                           "deprecated and will be removed in a future "
                           "version",

pandas/tests/frame/test_convert_to.py

@@ -83,8 +83,9 @@ def test_to_records_dt64(self):
             result = df.to_records(convert_datetime64=True)['index'][0]
             assert expected == result
 
-        rs = df.to_records(convert_datetime64=False)
-        assert rs['index'][0] == df.index.values[0]
+        with tm.assert_produces_warning(FutureWarning):
+            rs = df.to_records(convert_datetime64=False)
+            assert rs['index'][0] == df.index.values[0]
 
     def test_to_records_with_multindex(self):
         # GH3189