如何创建fabric2任务装饰器？

Question

让我们首先考虑一些使用fabric2的未分解的工作代码：

import traceback import inspect


from fabric2.tasks import task 
from fabric2 import Config, Connection


def get_function_name():
    return traceback.extract_stack(None, 2)[0][2]


def get_function_parameters_and_values():
    frame = inspect.currentframe().f_back
    args, _, _, values = inspect.getargvalues(frame)
    return ", ".join([str(i) for i in args])


@task def foo1(c, arg1):
    print(f'<{get_function_name()} {get_function_parameters_and_values()}>')

    def _inner():
        if int(arg1) < 5:
            print('arg1 is not big enough')
            return
        print('doing foo1 stuff')
    res = _inner()
    print(f'</{get_function_name}')
    return res


@task def foo2(c, arg1, arg2):
    print(f'<{get_function_name()} {get_function_parameters_and_values()}>')

    def _inner():
        if int(arg1) < 5 and int(arg2) < 5:
            print('arg1 & arg2 are not big enough')
            return
        print('doing foo2 stuff')
    res = _inner()
    print(f'</{get_function_name}')
    return res

现在，正如您在上面看到的，有一些代码重复，我想以包装器/装饰器的方式考虑出来。。。如果我尝试这样的方法，问题就来了：

def wrap(func):
    def wrapped(*args, **kwargs):
        print('begin')
        res = func(*args, **kwargs)
        print('end')
    return wrapped


@task
@wrap
def foo3(c, arg1):
    if int(arg1) < 5:
        print('arg1 is not big enough')
        return
    print('doing foo3 stuff')


@wrap
@task
def foo4(c, arg1):
    if int(arg1) < 5:
        print('arg1 is not big enough')
        return
    print('doing foo4 stuff')

如果我运行这两个任务中的任何一个，都会出现异常，例如：

(py364_32) D:\sources\personal\python\bplfab\examples>fab2 foo3 --arg1=3
Traceback (most recent call last):
  File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 160, in argspec
    context_arg = arg_names.pop(0)
IndexError: pop from empty list

During handling of the above exception, another exception occurred:

    Traceback (most recent call last):
      File "d:\software\python364_32\Lib\runpy.py", line 193, in _run_module_as_main
        "__main__", mod_spec)
      File "d:\software\python364_32\Lib\runpy.py", line 85, in _run_code
        exec(code, run_globals)
      File "D:\virtual_envs\py364_32\Scripts\fab2.exe\__main__.py", line 7, in <module>
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\program.py", line 352, in run
        self.parse_collection()
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\program.py", line 444, in parse_collection
        self.load_collection()
      File "d:\virtual_envs\py364_32\lib\site-packages\fabric2\main.py", line 87, in load_collection
        super(Fab, self).load_collection()
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\program.py", line 661, in load_collection
        module, parent = loader.load(coll_name)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\loader.py", line 76, in load
        module = imp.load_module(name, fd, path, desc)
      File "d:\virtual_envs\py364_32\lib\imp.py", line 235, in load_module
        return load_source(name, filename, file)
      File "d:\virtual_envs\py364_32\lib\imp.py", line 172, in load_source
        module = _load(spec)
      File "<frozen importlib._bootstrap>", line 684, in _load
      File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
      File "<frozen importlib._bootstrap_external>", line 678, in exec_module
      File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
      File "D:\sources\personal\python\bplfab\examples\fabfile.py", line 59, in <module>
        @wrap
      File "d:\virtual_envs\py364_32\lib\site-packages\fabric2\tasks.py", line 71, in task
        return invoke.task(*args, **kwargs)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 313, in task
        return klass(args[0], **kwargs)
      File "d:\virtual_envs\py364_32\lib\site-packages\fabric2\tasks.py", line 21, in __init__
        super(Task, self).__init__(*args, **kwargs)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 77, in __init__
        self.positional = self.fill_implicit_positionals(positional)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 168, in fill_implicit_positionals
        args, spec_dict = self.argspec(self.body)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 163, in argspec
        raise TypeError("Tasks must have an initial Context argument!")
    TypeError: Tasks must have an initial Context argument!

    (py364_32) D:\sources\personal\python\bplfab\examples>fab2 foo4 --arg1=3
    Traceback (most recent call last):
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 160, in argspec
        context_arg = arg_names.pop(0)
    IndexError: pop from empty list

    During handling of the above exception, another exception occurred:

    Traceback (most recent call last):
      File "d:\software\python364_32\Lib\runpy.py", line 193, in _run_module_as_main
        "__main__", mod_spec)
      File "d:\software\python364_32\Lib\runpy.py", line 85, in _run_code
        exec(code, run_globals)
      File "D:\virtual_envs\py364_32\Scripts\fab2.exe\__main__.py", line 7, in <module>
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\program.py", line 352, in run
        self.parse_collection()
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\program.py", line 444, in parse_collection
        self.load_collection()
      File "d:\virtual_envs\py364_32\lib\site-packages\fabric2\main.py", line 87, in load_collection
        super(Fab, self).load_collection()
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\program.py", line 661, in load_collection
        module, parent = loader.load(coll_name)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\loader.py", line 76, in load
        module = imp.load_module(name, fd, path, desc)
      File "d:\virtual_envs\py364_32\lib\imp.py", line 235, in load_module
        return load_source(name, filename, file)
      File "d:\virtual_envs\py364_32\lib\imp.py", line 172, in load_source
        module = _load(spec)
      File "<frozen importlib._bootstrap>", line 684, in _load
      File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
      File "<frozen importlib._bootstrap_external>", line 678, in exec_module
      File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
      File "D:\sources\personal\python\bplfab\examples\fabfile.py", line 59, in <module>
        @wrap
      File "d:\virtual_envs\py364_32\lib\site-packages\fabric2\tasks.py", line 71, in task
        return invoke.task(*args, **kwargs)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 313, in task
        return klass(args[0], **kwargs)
      File "d:\virtual_envs\py364_32\lib\site-packages\fabric2\tasks.py", line 21, in __init__
        super(Task, self).__init__(*args, **kwargs)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 77, in __init__
        self.positional = self.fill_implicit_positionals(positional)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 168, in fill_implicit_positionals
        args, spec_dict = self.argspec(self.body)
      File "d:\virtual_envs\py364_32\lib\site-packages\invoke\tasks.py", line 163, in argspec
        raise TypeError("Tasks must have an initial Context argument!")
    TypeError: Tasks must have an initial Context argument!

似乎已经有一个公开的问题与此https://github.com/pyinvoke/invoke/issues/555有关，但到目前为止，我还没有找到解决方法

你能解释一下我做错了什么吗？但最重要的是，您能否提供一种方法来解决这个fabric2“限制”，并能够创建一个decorator，允许我使用inspect来捕获任务的名称以及在命令行中传递的参数

提前谢谢