from contextlib import contextmanager

@contextmanager
def access_resource(name):
    print('Acquiring resource:', name)
    res = []
    try:
        yield res
    finally:
        print('Releasing resource:', name, res)

with access_resource('To-Do List') as xs:
    print('Add To-Do Items')
    xs.append('Item 1')
    xs.append('Item 2')

with access_resource('Finished List') as xs:
    raise KeyError('Impossible')