Python:记录所有类的方法而不修饰每个方法

Question

我想在某些类中记录每个方法调用.我本可以做到的

class Class1(object):
    @log
    def method1(self, *args):
        ...
    @log
    def method2(self, *args):
        ...

但是我在每个班级都有很多方法,而且我不想单独装饰每一个.目前,我尝试使用带有元类的hack(覆盖我记录的类',__getattribute__这样如果我尝试获取方法,它将返回一个日志记录方法):

class LoggedMeta(type):
    def __new__(cls, name, bases, attrs):
        def __getattribute__(self, name_):
            attr = super().__getattribute__(name_)
            if isinstance(attr, (types.MethodType, types.FunctionType)) and not name_.startswith("__"):
                return makeLogged(attr) #This returns a method that first logs the method call, and then calls the original method.
            return attr
        attrs["__getattribute__"] = __getattribute__
    return type.__new__(cls, name, bases, attrs)

class Class1(object):
    __metaclass__ = LoggedMeta
    def method1(self, *args):
        ...

但是,我使用的是Python 2.X,而super()语法不起作用.当我调用super时,我没有__getattribute__类(但我确实有它的类名),所以我不能使用旧的超级语法super(Class, Inst).

我之前尝试过使用元类,但是覆盖所有方法而不是__getattribute__,但我也想记录静态方法调用,它们给了我一些麻烦.

我搜索了这类问题,但发现没有人试图以这种方式改变课程.

任何想法或帮助将非常感激.

编辑:我的解决方案是这个(主要取自这个线程):

import inspect, types

CLASS = 0
NORMAL = 1
STATIC = 2

class DecoratedMethod(object):

    def __init__(self, func, type_):
        self.func = func
        self.type = type_

    def __get__(self, obj, cls=None):
        def wrapper(*args, **kwargs):
            print "before"
            if self.type == CLASS:
                #classmethods (unlike normal methods) reach this stage as bound methods, but args still contains the class
                #as a first argument, so we omit it.
                ret = self.func(*(args[1:]), **kwargs)
            else:
                ret = self.func(*args, **kwargs)
            print "after"
            return ret
        for attr in "__module__", "__name__", "__doc__":
            setattr(wrapper, attr, getattr(self.func, attr))
        if self.type == CLASS:
            return types.MethodType(wrapper, cls, type)
        elif self.type == NORMAL:
            return types.MethodType(wrapper, obj, cls) 
        else:
            return wrapper

def decorate_class(cls):
    for name, meth in inspect.getmembers(cls):
        if inspect.ismethod(meth):
            if inspect.isclass(meth.im_self):
                # meth is a classmethod
                setattr(cls, name, DecoratedMethod(meth, CLASS))
            else:
                # meth is a regular method
                setattr(cls, name, DecoratedMethod(meth, NORMAL))
        elif inspect.isfunction(meth):
            # meth is a staticmethod
            setattr(cls, name, DecoratedMethod(meth, STATIC))
    return cls


@decorate_class
class MyClass(object):

    def __init__(self):
        self.a = 10
        print "__init__"

    def foo(self):
        print self.a

    @staticmethod
    def baz():
        print "baz"

    @classmethod
    def bar(cls):
        print "bar"

后来我把它清理了一下,但那是解决方案的本质.我需要类,静态和普通方法之间的这种区别,因为我想要

inst = MyClass()
assert type(inst.baz) == types.FunctionType
assert type(inst.foo) == types.MethodType
assert type(inst.bar) == types.MethodType

Answer 1

你为什么不改变类对象？

您可以在类中查看方法,dir(MyClass)并使用包装版本替换它们...类似于:

def logify(klass):
    for member in dir(klass):
        if not callable(getattr(klass, method))
            continue # skip attributes
        setattr(klass, method, log(method))

修补这样的东西...应该工作......

Answer 2

如果目标是通过简单地记录调用和响应来使代码更易于调试，请查看自动日志记录模块。只需要一个注释即可 =)

https://pythonhosted.org/Autologging/examples-traced.html

pip install Autologging

。

# my_module.py

from autologging import traced


@traced
class MyClass:

   def __init__(self):
      self._value = "ham"

   def my_method(self, arg, keyword=None):
      return "%s, %s, and %s" % (arg, self._value, keyword)

。

>>> import logging, sys
>>> from autologging import TRACE
>>> logging.basicConfig(level=TRACE, stream=sys.stdout,
...     format="%(levelname)s:%(name)s:%(funcName)s:%(message)s")
>>> from my_module import MyClass
>>> my_obj = MyClass()
TRACE:my_module.MyClass:__init__:CALL *() **{}
TRACE:my_module.MyClass:__init__:RETURN None
>>> my_obj.my_method("spam", keyword="eggs")
TRACE:my_module.MyClass:my_method:CALL *('spam',) **{'keyword': 'eggs'}
TRACE:my_module.MyClass:my_method:RETURN 'spam, ham, and eggs'
'spam, ham, and eggs'