decorating a method in python -
i making little wrapper module public library, library has lot of repetition, after object creation, maybe methods require same data elements.
i have pass same data in wrapper class, don't want pass same thing on , over. store data in wrapper class , apply if not included in method. if things hairy down road, want method arguments overwrite class defaults. here code snippet illustrates goals.
class stackoverflow(): def __init__(self,**kwargs): self.gen_args = {} #optionally add repeated element object if 'index' in kwargs: self.gen_args['index'] = kwargs['index'] if 'doc_type' in kwargs: self.gen_args['doc_type'] = kwargs['doc_type'] #this problem def gen_args(fn): def inner(self,*args,**kwargs): kwargs.update(self.gen_args) return fn(*args,**kwargs) return inner #there bunch of these do_stuffs require index , doc_type @gen_args def do_stuff(self,**kwargs): print(kwargs['index']) print(kwargs['doc_type']) #just send arguments method print("case a") = stackoverflow() a.do_stuff(index=1,doc_type=2) #add them class , have methods use them without having specify #them each time print("case b") b = stackoverflow(index=1,doc_type=2) b.do_stuff() #the arguments specified in method should overwrite class values print("case c") c = stackoverflow(index=1,doc_type=2) c.do_stuff(index=3,doc_type=4) edit:
so question is, how fix gen_args or there better way this? specific error code is: return fn(*args,**kwargs) typeerror: do_stuff() missing 1 required positional argument: 'self'
i might use definition of inner:
def inner(self,*args,**kwargs): return fn(self, *args,**dict(self.gen_args, **kwargs)) notes:
- this version provides
self, missing in version. - this gives priority passed-in
kwargs.