test_io.py 文件源码

def test_format(self):
        a = np.array([(1, 2), (3, 4)])
        c = BytesIO()
        # Sequence of formats
        np.savetxt(c, a, fmt=['%02d', '%3.1f'])
        c.seek(0)
        assert_equal(c.readlines(), [b'01 2.0\n', b'03 4.0\n'])

        # A single multiformat string
        c = BytesIO()
        np.savetxt(c, a, fmt='%02d : %3.1f')
        c.seek(0)
        lines = c.readlines()
        assert_equal(lines, [b'01 : 2.0\n', b'03 : 4.0\n'])

        # Specify delimiter, should be overiden
        c = BytesIO()
        np.savetxt(c, a, fmt='%02d : %3.1f', delimiter=',')
        c.seek(0)
        lines = c.readlines()
        assert_equal(lines, [b'01 : 2.0\n', b'03 : 4.0\n'])

        # Bad fmt, should raise a ValueError
        c = BytesIO()
        assert_raises(ValueError, np.savetxt, c, a, fmt=99)