decorator.py

#!/usr/bin/python3

import logging
import time
import functools
import types

logging.basicConfig(level=logging.DEBUG)

"""用类去写装饰器更加的灵活
"""
# 被装饰的函数，作为类对象初始化参数，然后调用的__call__方法

class use_logging_class(object):
    """docstring for use_logging_class"""
    def __init__(self, func):
        super(use_logging_class, self).__init__()  
        self._func = func
        functools.update_wrapper(self, self._func)

    def __call__(self, *args, **kwargs):
        start = time.time()
        self._func(*args, **kwargs)
        usetime = time.time()-start
        print("{0} func use time {1}.".format(self._func.__name__, usetime))

    def __get__(self, obj, cls):
        if obj is None:
            return self     #  return self如果通过类方法访问，这个描述符的时候根据惯例直接返回装饰器，也即描述符本身
        else:
            return types.MethodType(self, obj)  #绑定描述符到托管类实例


def use_logging(func):
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        start = time.time()
        func(*args, **kwargs)
        usetime = time.time()-start
        print("{0} func use time {1}.".format(func.__name__, usetime))
        
    return wrapper


#在装饰器的外面再封装一层变成，带参数的装饰器
def use_logging_with_arg(p = True):
    def use_logging(func):
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            start = time.time()
            func(*args, **kwargs)
            usetime = time.time()-start
            if p:
                print("{0} func use time {1}.".format(func.__name__, usetime))
        return wrapper
    return use_logging

@use_logging_with_arg(False)
def foo():
    print('i am foo func.')
    # logging.info('foo is running')
@use_logging_class
def bar():
    print('i am bar func.')


class TestDec(object):
    def __init__(self):
        pass

    @use_logging_class
    def t_print(self, line):
        print(line)


if __name__ == '__main__':
    foo()
    print(foo.__name__)
    print(bar.__name__)
    td = TestDec()
    td.t_print('hello')