TST: Use explicit NaT in test_structure_format

jjhelmus · jjhelmus · commit 0724f58bf999 · 2017-03-30T12:43:35.000-05:00
Using np.nan to fill a datetime64 array with NaT depends on the undefined behavior of a float64 to int64 cast, which may have different behaviors on non-x64 platforms. See numpy#8325. For this reason np.datetime64('NaT') should be used fill or set datetime64 arrays with NaT.
diff --git a/numpy/core/tests/test_arrayprint.py b/numpy/core/tests/test_arrayprint.py
@@ -141,7 +141,7 @@ def test_structure_format(self):
 
         # for issue #5692
         A = np.zeros(shape=10, dtype=[("A", "M8[s]")])
-        A[5:].fill(np.nan)
+        A[5:].fill(np.datetime64('NaT'))
         assert_equal(np.array2string(A),
                 "[('1970-01-01T00:00:00',) ('1970-01-01T00:00:00',) " +
                 "('1970-01-01T00:00:00',)\n ('1970-01-01T00:00:00',) " +
