test_umath.py 文件源码

def test_reduction(self):
        binary_funcs = (np.bitwise_or, np.bitwise_xor, np.bitwise_and)

        for dt in self.bitwise_types:
            zeros = np.array([0], dtype=dt)
            ones = np.array([-1], dtype=dt)
            for f in binary_funcs:
                msg = "dt: '%s', f: '%s'" % (dt, f)
                assert_equal(f.reduce(zeros), zeros, err_msg=msg)
                assert_equal(f.reduce(ones), ones, err_msg=msg)

        # Test empty reduction, no object dtype
        for dt in self.bitwise_types[:-1]:
            # No object array types
            empty = np.array([], dtype=dt)
            for f in binary_funcs:
                msg = "dt: '%s', f: '%s'" % (dt, f)
                tgt = np.array(f.identity, dtype=dt)
                res = f.reduce(empty)
                assert_equal(res, tgt, err_msg=msg)
                assert_(res.dtype == tgt.dtype, msg)

        # Empty object arrays use the identity.  Note that the types may
        # differ, the actual type used is determined by the assign_identity
        # function and is not the same as the type returned by the identity
        # method.
        for f in binary_funcs:
            msg = "dt: '%s'" % (f,)
            empty = np.array([], dtype=object)
            tgt = f.identity
            res = f.reduce(empty)
            assert_equal(res, tgt, err_msg=msg)

        # Non-empty object arrays do not use the identity
        for f in binary_funcs:
            msg = "dt: '%s'" % (f,)
            btype = np.array([True], dtype=object)
            assert_(type(f.reduce(btype)) is bool, msg)