Whatsnew, issue tag, test reordering.

Author: sstanovnik

doc/source/whatsnew/v0.19.0.txt

@@ -437,6 +437,7 @@ API changes
 - ``pd.Timedelta(None)`` is now accepted and will return ``NaT``, mirroring ``pd.Timestamp`` (:issue:`13687`)
 - ``Timestamp``, ``Period``, ``DatetimeIndex``, ``PeriodIndex`` and ``.dt`` accessor have gained a ``.is_leap_year`` property to check whether the date belongs to a leap year. (:issue:`13727`)
 - ``pd.read_hdf`` will now raise a ``ValueError`` instead of ``KeyError``, if a mode other than ``r``, ``r+`` and ``a`` is supplied. (:issue:`13623`)
+- ``.values`` will now return ``np.float64`` with a ``DataFrame`` with ``np.int64`` and ``np.uint64`` dtypes, conforming to ``np.find_common_type`` (:issue:`10364`, :issue:`13917`)
 
 
 

pandas/tests/frame/test_block_internals.py

@@ -104,6 +104,7 @@ def test_as_matrix_lcd(self):
         values = self.mixed_float.as_matrix(['C'])
         self.assertEqual(values.dtype, np.float16)
 
+        # GH 10364
         # B uint64 forces float because there are other signed int types
         values = self.mixed_int.as_matrix(['A', 'B', 'C', 'D'])
         self.assertEqual(values.dtype, np.float64)

pandas/tests/types/test_cast.py

@@ -192,33 +192,42 @@ def test_possibly_convert_objects_copy(self):
 
 
 class TestCommonTypes(tm.TestCase):
-    def setUp(self):
-        super(TestCommonTypes, self).setUp()
-
     def test_numpy_dtypes(self):
+        # identity
         self.assertEqual(_find_common_type([np.int64]), np.int64)
         self.assertEqual(_find_common_type([np.uint64]), np.uint64)
         self.assertEqual(_find_common_type([np.float32]), np.float32)
         self.assertEqual(_find_common_type([np.object]), np.object)
 
+        # into ints
         self.assertEqual(_find_common_type([np.int16, np.int64]),
                          np.int64)
         self.assertEqual(_find_common_type([np.int32, np.uint32]),
                          np.int64)
-        self.assertEqual(_find_common_type([np.object, np.float32]),
-                         np.object)
-        self.assertEqual(_find_common_type([np.object, np.int16]),
-                         np.object)
-        self.assertEqual(_find_common_type([np.int16, np.float64]),
-                         np.float64)
+        self.assertEqual(_find_common_type([np.uint16, np.uint64]),
+                         np.uint64)
+
+        # into floats
+        self.assertEqual(_find_common_type([np.float16, np.float32]),
+                         np.float32)
         self.assertEqual(_find_common_type([np.float16, np.int16]),
                          np.float32)
+        self.assertEqual(_find_common_type([np.float32, np.int16]),
+                         np.float32)
+        self.assertEqual(_find_common_type([np.uint64, np.int64]),
+                         np.float64)
+        self.assertEqual(_find_common_type([np.int16, np.float64]),
+                         np.float64)
         self.assertEqual(_find_common_type([np.float16, np.int64]),
                          np.float64)
+
+        # into others
         self.assertEqual(_find_common_type([np.complex128, np.int32]),
                          np.complex128)
-        self.assertEqual(_find_common_type([np.uint64, np.int64]),
-                         np.float64)
+        self.assertEqual(_find_common_type([np.object, np.float32]),
+                         np.object)
+        self.assertEqual(_find_common_type([np.object, np.int16]),
+                         np.object)
 
     def test_pandas_dtypes(self):
         with self.assertRaises(TypeError):