如何用 Python Popen 做多个参数?

问题描述

我正在尝试制作一个带有按钮的 PyGtk Gui.当用户按下此按钮时，gnome-terminal 提示用户输入密码.

I am trying to make a PyGtk Gui, that has a button. When the user presses this button, gnome-terminal prompts the user to write their password.

然后它将为 gedit JQuery 片段.

Then it will clone this Git repository for gedit JQuery snippets.

然后，它将 js.xml 文件复制到 /usr/share/gedit/plugins/snippets/js.xml

And then, it copies the js.xml file to /usr/share/gedit/plugins/snippets/js.xml

最后，它强行删除了 Git 存储库.

In the end, it forcefully removes the Git repository.

命令:

gnome-terminal -x sudo git clone git://github.com/pererinha/gedit-snippet-jquery.git && sudo cp -f gedit-snippet-jquery/js.xml /usr/share/gedit/plugins/snippets/js.xml && sudo rm -rf gedit-snippet-jquery

它在我的终端上运行良好.

It works fine in my terminal.

但是， 通过它刚刚打开的 GUI，我添加了我的密码，按 Enter，然后它再次关闭.

But, via the GUI it just opens, I add my password, press enter, and then it closes again.

我只想将命令运行到第一个 &&

I'd like to only run the command to the first &&

这是我的 Python 函数(带命令):

def on_install_jquery_code_snippet_for_gedit_activate(self, widget):
    """ Install Jquery code snippet for Gedit. """
    cmd="gnome-terminal -x sudo git clone git://github.com/pererinha/gedit-snippet-jquery.git && sudo cp -f gedit-snippet-jquery/js.xml /usr/share/gedit/plugins/snippets/js.xml && sudo rm -rf gedit-snippet-jquery"
    p = Popen(cmd, shell=True, stdin=PIPE, stdout=PIPE, stderr=STDOUT,
             close_fds=False)
    self.status.set_text(p.stdout.read()) #show response in 'status

推荐答案

要直接回答您的问题，请阅读下文.但是您的程序存在很多问题，其中一些我在更好的实践"中进行了介绍.

To directly answer your question, read below. But there's a lot of problems with your program, some of which I cover in "Better practice."

默认情况下，subprocess.Popen 命令以字符串列表的形式提供.

By default, subprocess.Popen commands are supplied as a list of strings.

但是，您也可以使用 shell 参数来执行格式与在 shell 提示符下键入时完全一样"的命令.

However, you can also you can use the shell argument to execute a command "formatted exactly as it would be when typed at the shell prompt."

否:

>>> p = Popen("cat -n file1 file2")

是的:

>>> p = Popen("cat -n file1 file2", shell=True)
>>> p = Popen(["cat", "-n", "file1", "file2"])

这两个选项之间存在许多差异，并且每个选项都有有效的用例.我不会试图总结差异 - Popen docs 在这方面已经做得很好了.

There are a number of differences between these two options, and valid use cases for each. I won't attempt to summarize the differences- the Popen docs already do an excellent job of that.

所以，对于你的命令，你会做这样的事情:

So, in the case of your commands, you'd do something like this:

cmd = "gnome-terminal -x sudo git clone git://github.com/pererinha/gedit-snippet-jquery.git && sudo cp -f gedit-snippet-jquery/js.xml /usr/share/gedit/plugins/snippets/js.xml && sudo rm -rf gedit-snippet-jquery"
p = Popen(cmd, shell=True, stdin=PIPE, stdout=PIPE, stderr=STDOUT,
          close_fds=False)

更好的做法

但是，使用 Python 作为许多系统命令的包装器并不是一个好主意.至少，您应该将命令分解为单独的 Popen，以便可以充分处理非零退出.实际上，这个脚本似乎更适合作为 shell 脚本.但如果你坚持使用 Python，还有更好的做法.

Better practice

However, using Python as a wrapper for many system commands is not really a good idea. At the very least, you should be breaking up your commands into separate Popens, so that non-zero exits can be handled adequately. In reality, this script seems like it'd be much better suited as a shell script. But if you insist on Python, there are better practices.

os 模块 应该代替调用到 rm 和 cp.虽然我没有这方面的经验，但您可能想看看像 GitPython 这样的工具来与 Git 存储库交互.

The os module should take the place of calls to rm and cp. And while I have no experience with it, you might want to look at tools like GitPython to interact with Git repositories.

最后，你应该小心调用 gnome-terminal 和 sudo.并非所有 GNU/Linux 用户都运行 Ubuntu，也不是每个人都安装了 sudo 或 GNOME 终端仿真器.在当前形式下，如果出现以下情况，您的脚本将会崩溃，而且毫无帮助:

Lastly, you should be careful about making calls to gnome-terminal and sudo. Not all GNU/Linux users run Ubuntu, and not everyone has sudo, or the GNOME terminal emulator installed. In its current form, your script will crash, rather unhelpfully, if:

• sudo 命令未安装
• 用户不在 sudoers 组中
• 用户未使用 GNOME 或其默认终端模拟器
• Git 未安装

如果您愿意假设您的用户正在运行 Ubuntu，那么调用 x-terminal-emulator 比直接调用 gnome-terminal 更好，因为它将调用他们安装的任何终端模拟器(例如，Xubuntu 用户的 xfce4-terminal).

If you're willing to assume your users are running Ubuntu, calling x-terminal-emulator is a much better option than calling gnome-terminal directly, as it will call whatever terminal emulator they've installed (e.g. xfce4-terminal for users of Xubuntu).

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