Python `with` 语句语义等价

我很困惑为什么在 Python docs 8.5hit_except的以下代码中是必要的。with 声明：

以下代码：

with EXPRESSION as TARGET:
    SUITE

在语义上等价于：

manager = (EXPRESSION)
enter = type(manager).__enter__
exit = type(manager).__exit__
value = enter(manager)
hit_except = False

try:
    TARGET = value
    SUITE
except:
    hit_except = True
    if not exit(manager, *sys.exc_info()):
        raise
finally:
    if not hit_except:
        exit(manager, None, None, None)

是不是像这样写得更简单，还是我缺少区别？

manager = (EXPRESSION)
enter = type(manager).__enter__
exit = type(manager).__exit__
value = enter(manager)

try:
    TARGET = value
    SUITE
except:
    if not exit(manager, *sys.exc_info()):
        raise
else:
    exit(manager, None, None, None)