test_datetime.py 文件源码

def test_datetime_dtype_creation(self):
        for unit in ['Y', 'M', 'W', 'D',
                     'h', 'm', 's', 'ms', 'us',
                     'ns', 'ps', 'fs', 'as']:
            dt1 = np.dtype('M8[750%s]' % unit)
            assert_(dt1 == np.dtype('datetime64[750%s]' % unit))
            dt2 = np.dtype('m8[%s]' % unit)
            assert_(dt2 == np.dtype('timedelta64[%s]' % unit))

        # Generic units shouldn't add [] to the end
        assert_equal(str(np.dtype("M8")), "datetime64")

        # Should be possible to specify the endianness
        assert_equal(np.dtype("=M8"), np.dtype("M8"))
        assert_equal(np.dtype("=M8[s]"), np.dtype("M8[s]"))
        assert_(np.dtype(">M8") == np.dtype("M8") or
                np.dtype("<M8") == np.dtype("M8"))
        assert_(np.dtype(">M8[D]") == np.dtype("M8[D]") or
                np.dtype("<M8[D]") == np.dtype("M8[D]"))
        assert_(np.dtype(">M8") != np.dtype("<M8"))

        assert_equal(np.dtype("=m8"), np.dtype("m8"))
        assert_equal(np.dtype("=m8[s]"), np.dtype("m8[s]"))
        assert_(np.dtype(">m8") == np.dtype("m8") or
                np.dtype("<m8") == np.dtype("m8"))
        assert_(np.dtype(">m8[D]") == np.dtype("m8[D]") or
                np.dtype("<m8[D]") == np.dtype("m8[D]"))
        assert_(np.dtype(">m8") != np.dtype("<m8"))

        # Check that the parser rejects bad datetime types
        assert_raises(TypeError, np.dtype, 'M8[badunit]')
        assert_raises(TypeError, np.dtype, 'm8[badunit]')
        assert_raises(TypeError, np.dtype, 'M8[YY]')
        assert_raises(TypeError, np.dtype, 'm8[YY]')
        assert_raises(TypeError, np.dtype, 'm4')
        assert_raises(TypeError, np.dtype, 'M7')
        assert_raises(TypeError, np.dtype, 'm7')
        assert_raises(TypeError, np.dtype, 'M16')
        assert_raises(TypeError, np.dtype, 'm16')