1 import types

     2 

     3 class Tracing:

     4     def __init__(self, name, bases, namespace):

     5         """Create a new class."""

     6         self.__name__ = name

     7         self.__bases__ = bases

     8         self.__namespace__ = namespace

     9     def __call__(self):

    10         """Create a new instance."""

    11         return Instance(self)

    12 

    13 class Instance:

    14     def __init__(self, klass):

    15         self.__klass__ = klass

    16     def __getattr__(self, name):

    17         try:

    18             value = self.__klass__.__namespace__[name]

    19         except KeyError:

    20             raise AttributeError, name

    21         if type(value) is not types.FunctionType:

    22             return value

    23         return BoundMethod(value, self)

    24 

    25 class BoundMethod:

    26     def __init__(self, function, instance):

    27         self.function = function

    28         self.instance = instance

    29     def __call__(self, *args):

    30         print "calling", self.function, "for", self.instance, "with", args

    31         return apply(self.function, (self.instance,) + args)

    32 

    33 Trace = Tracing('Trace', (), {})

    34 

    35 class MyTracedClass(Trace):

    36     def method1(self, a):

    37         self.a = a

    38     def method2(self):

    39         return self.a

    40 

    41 aninstance = MyTracedClass()

    42 

    43 aninstance.method1(10)

    44 

    45 print aninstance.method2()