DEPR: convert_datetime64 parameter in to_records()

Author: reidy-p

doc/source/whatsnew/v0.23.0.txt

@@ -728,6 +728,7 @@ Deprecations
 - The ``broadcast`` parameter of ``.apply()`` is deprecated in favor of ``result_type='broadcast'`` (:issue:`18577`)
 - The ``reduce`` parameter of ``.apply()`` is deprecated in favor of ``result_type='reduce'`` (:issue:`18577`)
 - The ``order`` parameter of :func:`factorize` is deprecated and will be removed in a future release (:issue:`19727`)
+- The ``convert_datetime64`` parameter has been deprecated and the default value is now ``False`` in :func:`to_records` as the NumPy bug motivating this parameter has been resolved (:issue:`18160`).
 
 .. _whatsnew_0230.prior_deprecations:
 

pandas/core/frame.py

@@ -1207,7 +1207,7 @@ def from_records(cls, data, index=None, exclude=None, columns=None,
 
         return cls(mgr)
 
-    def to_records(self, index=True, convert_datetime64=True):
+    def to_records(self, index=True, convert_datetime64=False):
         """
         Convert DataFrame to record array. Index will be put in the
         'index' field of the record array if requested
@@ -1216,14 +1216,23 @@ def to_records(self, index=True, convert_datetime64=True):
         ----------
         index : boolean, default True
             Include index in resulting record array, stored in 'index' field
-        convert_datetime64 : boolean, default True
+        convert_datetime64 : boolean, default False
+            .. deprecated:: 0.23.0
+
             Whether to convert the index to datetime.datetime if it is a
             DatetimeIndex
 
         Returns
         -------
         y : recarray
         """
+
+        if convert_datetime64:
+            warnings.warn("The 'convert_datetime64' parameter is "
+                          "deprecated and will be removed in a future "
+                          "version",
+                          FutureWarning, stacklevel=2)
+
         if index:
             if is_datetime64_any_dtype(self.index) and convert_datetime64:
                 ix_vals = [self.index.to_pydatetime()]

pandas/tests/frame/test_convert_to.py

@@ -78,7 +78,10 @@ def test_to_records_dt64(self):
         df = DataFrame([["one", "two", "three"],
                         ["four", "five", "six"]],
                        index=date_range("2012-01-01", "2012-01-02"))
-        assert df.to_records()['index'][0] == df.index[0]
+        with tm.assert_produces_warning(FutureWarning):
+            expected = df.index[0]
+            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]