一、装饰器无参数
1.原函数无参数
def wrap_in_tag_b(fn): # wrap_in_tag_b 是真正的装饰器
def wrapped():
return "<b>" + fn() + "</b>"
return wrapped
def wrap_in_tag_i(fn):
def wrapped():
return "<i>" + fn() + "</i>"
return wrapped
@wrap_in_tag_b
@wrap_in_tag_i
def hello():
return "hello"
print(hello()) # returns "<b><i>hello world</i></b>"
2.原函数带参数
def wrap_in_tag_b(fn):
def wrapped(arg): # arg 是原函数参数
return "<b>" + fn(arg) + "</b>"
return wrapped
def wrap_in_tag_i(fn):
def wrapped(arg): # arg 是原函数参数
return "<i>" + fn(arg) + "</i>"
return wrapped
@wrap_in_tag_b
@wrap_in_tag_i
def hello(name):
return "hello {}".formar(name)
print(hello('Jack'))
二、装饰器带参数
1.原函数无参数
def wrap_in_tag(deco_arg):
# 装饰器参数：deco_arg
# 可以在任意位置使用
def real_decorator(func): # real_decorator才是即将返回的真正的装饰器
# 原函数参数：func_arg
# 只可以在此位置使用
def wrapped() :
return "<{0}>{1}</{0}>".format(deco_arg, func())
return wrapped
return real_decorator
@wrap_in_tag('b')
@wrap_in_tag('i')
def hello():
return "hello"
print(hello())
2.原函数带参数
def wrap_in_tag(deco_arg):
# 装饰器参数：deco_arg
# 可以在任意位置使用
def real_decorator(func): # real_decorator才是即将返回的真正的装饰器
def wrapped(func_arg):
# 原函数参数：func_arg
# 只可以在此位置使用
return "<{0}>{1}</{0}>".format(deco_arg, func(func_arg))
return wrapped
return real_decorator
@wrap_in_tag('b')
@wrap_in_tag('i')
def hello(name):
return "hello {}".format(name)
print(hello('Jack'))
三、装饰器类
1.原函数无参数
class wrap_in_tag(object):
def __init__(self, deco_arg):
self.tag = deco_arg # 装饰器参数：deco_arg
def __call__(self, func):
def newf(): # 原函数无参数
return "<{0}>{1}</{0}>".format(self.tag, func())
return newf
@wrap_in_tag('b')
@wrap_in_tag('i')
def hello():
return 'hello'
print(hello())
2.原函数带参数
class wrap_in_tag(object):
def __init__(self, deco_arg):
self.tag = deco_arg # 装饰器参数：deco_arg
def __call__(self, func):
def newf(func_arg): # 原函数参数: func_arg
return "<{0}>{1}</{0}>".format(self.tag, func(func_arg))
return newf
@wrap_in_tag('b')
@wrap_in_tag('i')
def hello(name):
return "hello {}".format(name)
print(hello('Jack'))
四、用装饰器装饰类
1.用函数作为装饰器
def wrap_in_tag(deco_arg):
def real_decorator(func):
def wrapped(self, func_arg): # 类方法接收第一个参数都是self，这个必须有，而无论func_arg是否有!!!
return "<{0}>{1}</{0}>".format(deco_arg, func(func_arg))
return wrapped
return real_decorator
class foo(object):
@wrap_in_tag('b')
@wrap_in_tag('i')
def hello(self, name):
return 'hello {}".format(name)
@wrap_in_tag('b')
@wrap_in_tag('i')
def byebye(self, name):
return 'byebye {}".format(name)
f = foo()
print(f.hello('Jack')
2.用类作为装饰器
class wrap_in_tag(object):
def __init__(self, deco_arg):
self.tag = deco_arg
def __call__(self, func):
def newf(slf, func_arg): # slf必须！self被占用了，那就给第一个参数另一个名字slf（随便）
return "<{0}>{1}</{0}>".format(self.tag, func(func_arg))
return newf
class foo(object):
@wrap_in_tag('b')
@wrap_in_tag('i')
def hello(self, name):
return 'hello {}".format(name)
@wrap_in_tag('b')
@wrap_in_tag('i')
def byebye(self, name):
return 'byebye {}".format(name)
f = foo()
print(f.hello('Jack'))
