使用装饰器对性能的影响 [英] Performance impact of using decorators

问题描述

我正在使用cherrypy构建一个应用程序，并且已经开始广泛使用

装饰器了。很多暴露的功能看起来像：


@expose

@startTransactrionAndBuildPage

@partOfTabUi（tabId）

@convert（arg1 = int，arg2 = str）

def do_main_page（self，arg1，arg2）：

一些代码

我非常喜欢装饰师并且非常喜欢使用它们。我已经准备好了，在python中函数调用很昂贵。在上面的例子中，解释器是否调用了5种不同的函数？

I''m building an application with cherrypy and have started using
decorators quite extensively. A lot of my exposed functions look like:

@expose
@startTransactrionAndBuildPage
@partOfTabUi(tabId)
@convert(arg1=int, arg2=str)
def do_main_page(self, arg1, arg2):
some code
I''ve become really fond of decorators and use them quite a lot. I''ve
also ready that function calls are expensive in python. In the above
example, does the interpreter call 5 different functions?

推荐答案

vinjvinj< vi ******@gmail.com>写道：

vinjvinj <vi******@gmail.com> wrote:

我正在构建一个带有cherrypy的应用程序，并且已经开始广泛使用
装饰器。很多我公开的函数看起来像：

@expose
@startTransactrionAndBuildPage
@partOfTabUi（tabId）
@convert（arg1 = int，arg2 = str）
def do_main_page（self，arg1，arg2）：
一些代码

我已经非常喜欢装饰器并且使用它们了很多。我已经准备好了python中的函数调用很昂贵。在上面的示例中，解释器是否调用了5个不同的函数？

I''m building an application with cherrypy and have started using
decorators quite extensively. A lot of my exposed functions look like:

@expose
@startTransactrionAndBuildPage
@partOfTabUi(tabId)
@convert(arg1=int, arg2=str)
def do_main_page(self, arg1, arg2):
some code

I''ve become really fond of decorators and use them quite a lot. I''ve
also ready that function calls are expensive in python. In the above
example, does the interpreter call 5 different functions?

在执行时，可能是6（两个装饰器没有args，加上2

每个w / args）;在调用时，它取决于装饰器是什么
做的（如果每个都添加一个包装闭包，例如，那么

确实是5个嵌套调用）。不幸的是，我不太了解

今天的樱桃内部，所以我不知道每个装饰师在做什么

内部。

Alex

At def-execution time, presumably 6 (the two decorators w/o args, plus 2
each for those w/args); at call time, it depends what the decorators are
doing (if each adds exactly one wrapping closure, for example, there
will indeed be 5 nested calls). Unfortunately I do not know much of
today''s cherrypy internals, so I don''t know what each decorator is doing
internally.
Alex

vinjvinj写道：

vinjvinj wrote:

我正在构建一个带有cherrypy的应用程序并已开始使用
装饰者相当广泛。很多我公开的函数看起来像：

@expose
@startTransactrionAndBuildPage
@partOfTabUi（tabId）
@convert（arg1 = int，arg2 = str）
def do_main_page（self，arg1，arg2）：
一些代码

我已经非常喜欢装饰器而且使用它们非常多。我已经准备好了python中的函数调用很昂贵。在上面的示例中，解释器是否调用了5个不同的函数？

I''m building an application with cherrypy and have started using
decorators quite extensively. A lot of my exposed functions look like:

@expose
@startTransactrionAndBuildPage
@partOfTabUi(tabId)
@convert(arg1=int, arg2=str)
def do_main_page(self, arg1, arg2):
some code
I''ve become really fond of decorators and use them quite a lot. I''ve
also ready that function calls are expensive in python. In the above
example, does the interpreter call 5 different functions?

如果没有读取代码我就不能确定，但​​这肯定是在寻找比如

经典的给一个只有锤子的男人看起来像钉子一样

解决方案。我不会告诉你，装饰者不是所有编程问题的答案，因为你已经知道了在你心中:-)


问候

Steve

-

Steve Holden [phone] [phone]

Holden Web LLC / Ltd www.holdenweb.com

Love我喜欢我的博客holdenweb.blogspot.com

Without reading your code I can''t be sure, but this is sure looking like
the classic "to a man with only a hammer all problems look like a nail"
solution. I''m not going to tell you that decorators aren''t the answer to
all programming problems, because you already know that in your heart :-)

regards
Steve
--
Steve Holden [phone] [phone]
Holden Web LLC/Ltd www.holdenweb.com
Love me, love my blog holdenweb.blogspot.com

>>解。我不会告诉你装饰器不是

>> solution. I''m not going to tell you that decorators aren''t the answer to

所有编程问题的答案，因为你已经知道了，在你心中： -

all programming problems, because you already know that in your heart :-

我当时很害怕。曝光装饰器是唯一一个带有cherrypy的
。其他的是我的，格式如下：


def decorator（func）：

def wrapper（self，* args，** kwargs）

一些代码

返回包装器


我会坚持我目前正在做的事情并最终（如果需要的话）

来自性能视角）将三者合并为一个

装饰器。我还需要最终添加一个缓存docrator.Do其他

人有这个问题，尤其是开发Web应用程序。

有多少装饰器，如果有的话，你用吗？


@expose - > cherrypy decorator

@startTransactrionAndBuildPage - >启动数据库事务，在会话中填充用户
。有一些错误处理。将页眉，页脚

和错误消息添加到页面。

@partOfTabUi - >除了顶级导航，我有标签级别

（带动作）在各个页面上导航

@convert - >这将boolean类似''True''或''0'转换为python True，

''231'' - > int

@cache - > （未实现，但会广告）。


我很想听听其他人使用装饰器的经验

用于构建Web应用程序。

I was fearing that. The expose decorator is the only one that comes
with cherrypy. The other ones are mine and are of the format:

def decorator(func):
def wrapper(self, *args, **kwargs)
some code
return wrapper

I''ll stick with what I''m doing currently and eventually (if the need
arises from a performance perspective) merge the three into one
decorator. I''ll also need to eventually add a caching docrator.Do other
people have this problem, especially for developing web applications.
How many decorators, if any, do you use?

@expose -> cherrypy decorator
@startTransactrionAndBuildPage -> starts a db transaction, populates
the user in the session. Does some error handling. Adds header, footer
and error messages to the page.
@partOfTabUi -> besides the top level navigation, I have tab level
(with actions) for navigation on individual pages
@convert -> this converts boolean like ''True'' or ''0'' to python True,
''231'' -> int
@cache -> (not implemented, but will ad it).

I would love to hear other people''s experience with using decorators
for web application building.

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