exemplo_decorator.py

#decorator 1
from datetime import datetime
import functools
import logging


def query_checker(*keys_to_check):
    """ Checks if a given key exists in the query string dictionary, if not, never executes the real handler and return status 400 """
    def real_decorator(func):
        @functools.wraps(func)
        def wraper(handler):
            def eval():
                for k in keys_to_check:
                    if k not in handler.request.GET:
                        handler.response.status_int = 400
                        handler.response.write('Query param: %s must be filled for this request' % keys_to_check)
                        return False
                return True
            return  func(handler) if eval() else None
        return wraper
    return real_decorator

#decorator 2
def log_time(func):
    def wraper(handler):
        start = datetime.now().replace(microsecond=0)
        func(handler)
        end = datetime.now().replace(microsecond=0)
        logging.debug(" Time to run request in seconds: %s" % str((end-start).seconds))
    return wraper

#decorated function:
@log_time
@query_checker('link')
    def get(self):
       #implementacao
       pass