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我正在使用 functools 制作一个装饰器，它允许我记录方法调用的详细信息。

我在这里得到了很多帮助来编写它……它不是我自己的，我仍在学习它是如何工作的……

我经常使用 ipython，当我使用时：

import Tools
imagetools = Tools.Tools()
imagetools.save_new_image ?

Type:       instancemethod
String Form:<bound method ImageTools.save_new_image of <ImageTools.ImageTools object      at    0x305d1d0>>
File:       /fs/corpus6/dpc/workspace/python/Modules/MiscTools.py
Definition: imagetools.save_new_image(self, *args, **kwargs)
Docstring:  <no docstring>

这是我的问题线...除了我还没有写文档字符串...：|

Definition: imagetools.save_new_image(self, *args, **kwargs)

我希望是：

save_new_image_clone(self, data, header, outfile,  coordmap)

包装：

import functools

def log_method(func):

@functools.wraps(func)
def wrapper(self, *args, **kwargs):
    self.__doc__ = func.__doc__
    # allows me to put the wrapper in helper methods that are sometimes major steps
    if check_for_True_in_last_arg(*args):
        log.debug('''Last arg is "True" which could indicate the caller 
intends the log to work on this method. For that behaviour, use the keyword arg:  log_this=True''')

    if 'log_this' in kwargs and kwargs['log_this'] is not False: 
        args_name = inspect.getargspec(func)[0][1:] #drop the 'self' arg
        args_dict = dict(list(itertools_izip(args_name, args)) + list(kwargs.iteritems()))
        method_name = wrapper.__name__
        args_dict_string = '\nMETHOD: ' + method_name + '\n'

        for k,v in args_dict.iteritems():
            if type(v) is not np.ndarray:
                args_dict_string += "%s: %s\n" %(k,v)

            elif type(v) is np.ndarray:
                args_dict_string += "NUMPY ARRAY:%s \nSHAPE:%s\n" %(k, str(v.shape))

        args_dict_string += '\n'
        log.info(args_dict_string)

    return func(self, *args, **kwargs) 

return wrapper

更新：在 ipython 中我这样做是为了看看发生了什么，但它还没有帮助我..

help??
Type:       _Helper
String Form:Type help() for interactive help, or help(object) for help about object.
File:       /usr/lib64/python2.7/site.py
Definition: help(self, *args, **kwds)
Source:

class _Helper(object):
"""Define the builtin 'help'.
This is a wrapper around pydoc.help (with a twist).

"""

def __repr__(self):
    return "Type help() for interactive help, " \
           "or help(object) for help about object."
def __call__(self, *args, **kwds):
    import pydoc
    return pydoc.help(*args, **kwds)

Call def:   help(self, *args, **kwds)
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1 回答 1

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您正在尝试做的事情——创建一个调用签名与被装饰的函数相同的装饰器——从头开始并不是一件简单的事情。有一个名为decorator的第三方模块，它可以做到这一点：

import decorator

@decorator.decorator
def log_method(func, *args, **kwargs):
    # allows me to put the wrapper in helper methods that are sometimes major steps
    if check_for_True_in_last_arg(*args):
        log.debug('''Last arg is "True" which could indicate the caller 
intends the log to work on this method. For that behaviour, use the keyword arg:  log_this=True''')

    if 'log_this' in kwargs and kwargs['log_this'] is not False: 
        args_name = inspect.getargspec(func)[0][1:] #drop the 'self' arg
        args_dict = dict(list(itertools_izip(args_name, args)) + list(kwargs.iteritems()))
        method_name = wrapper.__name__
        args_dict_string = '\nMETHOD: ' + method_name + '\n'

        for k,v in args_dict.iteritems():
            if type(v) is not np.ndarray:
                args_dict_string += "%s: %s\n" %(k,v)

            elif type(v) is np.ndarray:
                args_dict_string += "NUMPY ARRAY:%s \nSHAPE:%s\n" %(k, str(v.shape))

        args_dict_string += '\n'
        log.info(args_dict_string)

    return func(self, *args, **kwargs) 

class Tools(object):
    @log_method
    def save_new_image(self, data, header, outfile, coordmap):
        """
        Jazz the snaz output baz
        """

然后从 IPython：

In [14]: imagetools = Tools()

In [15]: imagetools.save_new_image?
Type:       instancemethod
String Form:<bound method Tools.save_new_image of <__main__.Tools object at 0xae1e20c>>
File:       /tmp/python-2973tNk.py
Definition: imagetools.save_new_image(self, data, header, outfile, coordmap)
Docstring:  Jazz the snaz output baz

如果您想查看实现此目的的 Python 代码，请查看decorator.FunctionMaker 类。它用于inspect找出原始函数的签名，然后使用字符串格式化来编写def-statement定义修饰函数。然后它调用exec code in evaldict执行字符串。

于 2014-08-01T17:43:41.387 回答