Is there a generic way for a function to reference itself?

Question

I can access a python function's attribute inside of function itself by below code:

def aa():     print aa.__name__     print aa.__hash__     # other simliar 

However, if above aa() function is a template for write other code, say bb(), I have to write:

def bb():     print bb.__name__     print bb.__hash__     # other simliar 

Is there a "pointer" similar to the self argument in a class method so I could write code like this?

def whatever():     print self.__name__     print self.__hash__     # other simliar 

I searched and found someone said to use the class to solve this problem, but that may be a trouble to redefine all the existing functions. Any suggestions?

Answer 1

There is no generic way for a function to refer to itself. Consider using a decorator instead. If all you want as you indicated was to print information about the function that can be done easily with a decorator:

from functools import wraps def showinfo(f):     @wraps(f)     def wrapper(*args, **kwds):          print(f.__name__, f.__hash__)          return f(*args, **kwds)     return wrapper  @showinfo def aa():     pass 

If you really do need to reference the function, then just add it to the function arguments:

def withself(f):     @wraps(f)     def wrapper(*args, **kwds):         return f(f, *args, **kwds)     return wrapper  @withself def aa(self):       print(self.__name__)       # etc. 

Edit to add alternate decorator:

You can also write a simpler (and probably faster) decorator that will make the wrapped function work correctly with Python's introspection:

def bind(f):     """Decorate function `f` to pass a reference to the function     as the first argument"""     return f.__get__(f, type(f))  @bind def foo(self, x):     "This is a bound function!"     print(self, x)   >>> foo(42) <function foo at 0x02A46030> 42 >>> help(foo) Help on method foo in module __main__:  foo(self, x) method of builtins.function instance     This is a bound function! 

This leverages Python's descriptor protocol: functions have a __get__ method that is used to create bound methods. The decorator simply uses the existing method to make the function a bound method of itself. It will only work for standalone functions, if you wanted a method to be able to reference itself you would have to do something more like the original solution.