使用python装饰器装饰功能的一部分

Question

I am trying to mock our git wrapper, so that we can test it. I plan to use mockproc python library which provides the functionality to mock any process name, with a provided script. It works something like this -

self.scripts.append( 'process-name', returncode=0, stdout="output to process" )
with self.scripts:
        run_and_handle_result()

I need to add a decorator layer over this so that I can do some extra things like handle retries. What I want is something like this -

@mockproc('git') # tells that we are mocking git
def test_something(mock_proc):
    mock_proc.set_script("sleep (60)")
    # Run some git command
    mockproc.check_exit_signal()

The problem is I want my decorator to handle the with self.scripts part. So what I want is that the decorator runs the function, setting the process name as git, which is simple. Then run the test function, which adds the script and add with self.script around the git command and then resumes the function.

Is there anyway to do it ? is a decorator bad way to implement it ? This is not a cosmetic requirement. I need this because in some of my commands there is retry logic, for which I need to provide more than one script to mockproc and run multiple times.

Answer 1

If I understood you correctly, you want to override a named free variable of a function. You can use fun.func_globals[some_name] = some_value . Eg

def x(a):
    pow2(a)

 x.func_globals['pow2'] = lambda y: y*y

 x(3) == 9