python wraps decorator

frominspectimportgetmembers, getargspec

fromfunctoolsimportwraps

 

defwraps_decorator(f):

    @wraps(f)

    defwraps_wrapper(*args,**kwargs):

        returnf(*args,**kwargs)

    returnwraps_wrapper

 

classSomeClass(object):

    @wraps_decorator

    defmethod(self, x, y):

        pass

 

obj=SomeClass()

forname, funcingetmembers(obj, predicate=inspect.ismethod):

    print"Member Name: %s"%name

    print"Func Name: %s"%func.func_name

    print"Args: %s"%getargspec(func)[0]

 

classmyDecorator(object):

 

    def__init__(self, fn):

        print"inside myDecorator.__init__()"

        self.fn=fn

 

    def__call__(self):

        self.fn()

        print"inside myDecorator.__call__()"

 

@myDecorator

defaFunction():

    print"inside aFunction()"

 

print"Finished decorating aFunction()"

 

aFunction()







你会发现，即使是你你用了functools的wraps，你在用getargspec时，参数也不见了。

要修正这一问，我们还得用Python的反射来解决，下面是相关的代码：

1

2

3

4

5

6

7

8

9

10

11

12

defget_true_argspec(method):

    argspec=inspect.getargspec(method)

    args=argspec[0]

    ifargsandargs[0]=='self':

        returnargspec

    ifhasattr(method,'__func__'):

        method=method.__func__

    ifnothasattr(method,'func_closure')ormethod.func_closure isNone:

        raiseException("No closure for method.")

 

    method=method.func_closure[0].cell_contents

    returnget_true_argspec(method)

当然，我相信大多数人的程序都不会去getargspec。所以，用functools的wraps应该够用了。

classMyApp():

    def__init__(self):

        self.func_map= {}

 

    defregister(self, name):

        deffunc_wrapper(func):

            self.func_map[name]= func

            returnfunc

        returnfunc_wrapper

 

    defcall_method(self, name=None):

        func= self.func_map.get(name, None)

        iffunc isNone:

            raiseException("No function registered against - "+ str(name))

        returnfunc()

 

app= MyApp()

 

@app.register('/')

defmain_page_func():

    return"This is the main page."

 

@app.register('/next_page')

defnext_page_func():

    return"This is the next page."

 

printapp.call_method('/')

printapp.call_method('/next_page')