fabric.api vs fabric.operations

Question

我是Python和Fabric的新手，使用的是Fabric==1.10.1和Python2.7.6。我不明白fabric.api和fabric.operations调用之间的区别，它们似乎都在做同样的事情。我应该在fabfile中使用哪一个？我注意到的一件事是，当我执行fabric.api.reboot()时，它确实会显示消息，

[127.0.0.1] out: Broadcast message from vagrant@localhost.localdomain
[127.0.0.1] out:
[127.0.0.1] out:    (/dev/pts/0) at 17:39 ...
[127.0.0.1] out:
[127.0.0.1] out:
[127.0.0.1] out:
[127.0.0.1] out:
[127.0.0.1] out: The system is going down for reboot NOW!
[127.0.0.1] out:

但是当我使用fabric.operations.reboot()时，它不会显示任何消息。

更新:实际上，似乎是fabric.operations.reboot()和fabric.api.reboot()产生了这个消息。

Answer 1

您可以使用这两种方法中的任何一种，但fabric.api是更好的选择。这是因为为了简单起见，它是导入其他fabric模块的地方。请看这里：

$ cat fabric/api.py                                                                                                                                                                                                                                          (env: selenium)
"""
Non-init module for doing convenient * imports from.

Necessary because if we did this in __init__, one would be unable to import
anything else inside the package -- like, say, the version number used in
setup.py -- without triggering loads of most of the code. Which doesn't work so
well when you're using setup.py to install e.g. ssh!
"""
from fabric.context_managers import (cd, hide, settings, show, path, prefix,
    lcd, quiet, warn_only, remote_tunnel, shell_env)
from fabric.decorators import (hosts, roles, runs_once, with_settings, task,
        serial, parallel)
from fabric.operations import (require, prompt, put, get, run, sudo, local,
    reboot, open_shell)
from fabric.state import env, output
from fabric.utils import abort, warn, puts, fastprint
from fabric.tasks import execute

fabric.api已经在为您导入fabric.operations.reboot。