我有一个由装饰器转移变量insurance_mode的问题。我将通过以下装饰器语句来实现:
@execute_complete_reservation(True)
def test_booking_gta_object(self):
self.test_select_gta_object()
但不幸的是，这种说法并不管用。也许也许有更好的办法来解决这个问题。
def execute_complete_reservation(test_case,insurance_mode):
def inner_function(self,*args,**kwargs):
self.test_create_qsf_query()
test_case(self,*args,**kwargs)
self.test_select_room_option()
if insurance_mode:
self.test_accept_insurance_crosseling()
else:
self.test_decline_insurance_crosseling()
self.test_configure_pax_details()
self.test_configure_payer_details
return inner_function
定义这个decoratorize函数来生成定制的decorator函数:
def decoratorize(FUN, **kw):
def foo(*args, **kws):
return FUN(*args, **kws, **kw)
return foo
可以这样用:
@decoratorize(FUN, arg1 = , arg2 = , ...)
def bar(...):
...
带参数的装饰器的语法有点不同——带参数的装饰器应该返回一个函数，该函数将接受一个函数并返回另一个函数。它应该返回一个普通的装饰器。有点困惑，对吧?我的意思是:
def decorator_factory(argument):
def decorator(function):
def wrapper(*args, **kwargs):
funny_stuff()
something_with_argument(argument)
result = function(*args, **kwargs)
more_funny_stuff()
return result
return wrapper
return decorator
在这里你可以读到更多关于这个主题的内容——也可以使用可调用对象来实现这个功能，这里也有解释。
在我的实例中，我决定通过一行lambda来解决这个问题，以创建一个新的decorator函数:
def finished_message(function, message="Finished!"):
def wrapper(*args, **kwargs):
output = function(*args,**kwargs)
print(message)
return output
return wrapper
@finished_message
def func():
pass
my_finished_message = lambda f: finished_message(f, "All Done!")
@my_finished_message
def my_func():
pass
if __name__ == '__main__':
func()
my_func()
执行时，输出:
Finished!
All Done!
也许不像其他解决方案那样可扩展，但对我来说是可行的。
下面是一个使用带有参数的装饰器的Flask示例。假设我们有一个路由'/user/name'，我们想要映射到他的主页。
def matchR(dirPath):
def decorator(func):
def wrapper(msg):
if dirPath[0:6] == '/user/':
print(f"User route '{dirPath}' match, calling func {func}")
name = dirPath[6:]
return func(msg2=name, msg3=msg)
else:
print(f"Input dirPath '{dirPath}' does not match route '/user/'")
return
return wrapper
return decorator
#@matchR('/Morgan_Hills')
@matchR('/user/Morgan_Hills')
def home(**kwMsgs):
for arg in kwMsgs:
if arg == 'msg2':
print(f"In home({arg}): Hello {kwMsgs[arg]}, welcome home!")
if arg == 'msg3':
print(f"In home({arg}): {kwMsgs[arg]}")
home('This is your profile rendered as in index.html.')
输出:
User route '/user/Morgan_Hills' match, calling func <function home at 0x000001DD5FDCD310>
In home(msg2): Hello Morgan_Hills, welcome home!
In home(msg3): This is your profile rendered as in index.html.
我猜你的问题是把参数传递给你的装饰师。这有点棘手，不简单。
下面是一个如何做到这一点的例子:
class MyDec(object):
def __init__(self,flag):
self.flag = flag
def __call__(self, original_func):
decorator_self = self
def wrappee( *args, **kwargs):
print 'in decorator before wrapee with flag ',decorator_self.flag
original_func(*args,**kwargs)
print 'in decorator after wrapee with flag ',decorator_self.flag
return wrappee
@MyDec('foo de fa fa')
def bar(a,b,c):
print 'in bar',a,b,c
bar('x','y','z')
打印:
in decorator before wrapee with flag foo de fa fa
in bar x y z
in decorator after wrapee with flag foo de fa fa
详见Bruce Eckel的文章。
def decorator(argument):
def real_decorator(function):
def wrapper(*args):
for arg in args:
assert type(arg)==int,f'{arg} is not an interger'
result = function(*args)
result = result*argument
return result
return wrapper
return real_decorator
装饰器的使用
@decorator(2)
def adder(*args):
sum=0
for i in args:
sum+=i
return sum
然后
adder(2,3)
生产
10
but
adder('hi',3)
生产
---------------------------------------------------------------------------
AssertionError Traceback (most recent call last)
<ipython-input-143-242a8feb1cc4> in <module>
----> 1 adder('hi',3)
<ipython-input-140-d3420c248ebd> in wrapper(*args)
3 def wrapper(*args):
4 for arg in args:
----> 5 assert type(arg)==int,f'{arg} is not an interger'
6 result = function(*args)
7 result = result*argument
AssertionError: hi is not an interger
