5.1 嵌套上下文管理的另类写法

当我们要写一个嵌套的上下文管理器时，可能会这样写

import contextlib

@contextlib.contextmanager
def test_context(name):
    print('enter, my name is {}'.format(name))

    yield

    print('exit, my name is {}'.format(name))

with test_context('aaa'):
    with test_context('bbb'):
        print('========== in main ============')

输出结果如下

enter, my name is aaa
enter, my name is bbb
========== in main ============
exit, my name is bbb
exit, my name is aaa

除此之外，你可知道，还有另一种嵌套写法

with test_context('aaa'), test_context('bbb'):
    print('========== in main ============')