使用pexpect和winpexpect

Question

我有一个使用pexpect的程序，需要在windows和linux上运行。pexpect和winpexpect具有相同的API，但spawn方法除外。在我的代码中支持两者的最好方法是什么？

我是这样想的：

import pexpect

use_winpexpect = True

try:
    import winpexpect
except ImportError:
    use_winpexpect = False

# Much later

if use_winpexpect:
    winpexpect.winspawn()
else:
    pexpect.spawn()

但我不确定这是否可行，或者这是一个好主意。

Answer 1

检查OS类型(可能对下游有用的信息，以及如何创建expect session对象)并基于此做出导入决策可能更容易。这是一个实际的示例，它生成适合操作系统的shell，并根据操作系统设置我们稍后将在脚本中查找的提示符，以确定命令何时完成：

# what platform is this script on?
import sys
if 'darwin' in sys.platform:
    my_os = 'osx'
    import pexpect
elif 'linux' in sys.platform:
    my_os = 'linux'
    import pexpect
elif 'win32' in sys.platform:
    my_os = 'windows'
    import winpexpect
else:
    my_os = 'unknown:' + sys.platform
    import pexpect

# now spawn the shell and set the prompt
prompt = 'MYSCRIPTPROMPT' # something we would never see in this session
if my_os == 'windows':
    command = 'cmd.exe'
    session = winpexpect.winspawn(command)
    session.sendline('prompt ' + prompt)
    session.expect(prompt) # this catches the setting of the prompt
    session.expect(prompt) # this catches the prompt itself.
else:
    command = '/bin/sh'
    session = pexpect.spawn(command)
    session.sendline('export PS1=' + prompt)
    session.expect(prompt) # this catches the setting of the prompt
    session.expect(prompt) # this catches the prompt itself.