传递给 Python 中所有实例方法的预处理参数

Question

class SimpleClass(object):
     def A(self, *args):
          ...
     def B(self, *args):
          ...
     def C(self, *args):
          ...

是否有办法捕获传递给 A、B、C 的参数，修改这些参数并将修改后的参数传递给 A、B、C，而无需修改现有代码？

编辑：

答案：使用类装饰器，用另一个装饰器装饰类的所有方法。

方法装饰器执行预处理。

Answer 1

试试这个：

from types import FunctionType

class SimpleClass(object):
    def A(self, *args):
        pass
    def B(self, *args):
        pass
    def C(self, *args):
        pass


def methods(cls):
    """List of all method in class."""
    return [x for x, y in cls.__dict__.items() if type(y) == FunctionType]

def args_decorator(method):
    """Decorator for SimpleClass methods"""
    def wrapper(self, *args):
        new_args = list(args)
        # change new_args here
        return method(self, *new_args)
    return wrapper


for method in methods(SimpleClass):
    setattr(SimpleClass, method, args_decorator(SimpleClass.__dict__[method]))

如果您可以更改您的SimpleClass，我建议您像这样使用装饰器：

def args_decorator(method):
    def wrapper(self, *args):
        new_args = list(args)
        # change new_args here
        return method(self, *new_args)
    return wrapper

class SimpleClass(object):
    @args_decorator
    def A(self, *args):
        pass
    @args_decorator
    def B(self, *args):
        pass
    @args_decorator
    def C(self, *args):
        pass