test_six.py 文件源码

def test_raise_from():
    try:
        try:
            raise Exception("blah")
        except Exception:
            ctx = sys.exc_info()[1]
            f = Exception("foo")
            six.raise_from(f, None)
    except Exception:
        tp, val, tb = sys.exc_info()
    if sys.version_info[:2] > (3, 0):
        # We should have done a raise f from None equivalent.
        assert val.__cause__ is None
        assert val.__context__ is ctx
    if sys.version_info[:2] >= (3, 3):
        # And that should suppress the context on the exception.
        assert val.__suppress_context__
    # For all versions the outer exception should have raised successfully.
    assert str(val) == "foo"