python 多个with 语句一起使用

with urlopen(URL) as remote, open(JSON, 'wb') as local:
    local.write(remote.read())

with open('in_file') as f:
    with open('out_file' 'w') as of:
        for line in f:
            of.write(line)
            ...

with open('in_file') as f, open('out_file' 'w') as of:
    for line in f:
        of.write(line)
        ...

with (
    open("face_model_choice.txt") as f,
    open("ttt.txt", "w") as of1,
    open("ttt2.txt", "w") as of2,
):
    for line in f:
        of1.write(line)
        of2.write(line)
		...