How to print Docstring of python function from inside the function itself?

shane87 picture shane87 · Jan 11, 2012 · Viewed 70.9k times · Source

I want to print the docstring of a python function from inside the function itself. for eg.

def my_function(self):
  """Doc string for my function."""
  # print the Docstring here.

At the moment I am doing this directly after my_function has been defined.

print my_function.__doc__

But would rather let the function do this itself.

I have tried calling print self.__doc__ print self.my_function.__doc__ and print this.__doc__ inside my_function but this did not work.

Answer

kindall picture kindall · Jan 11, 2012
def my_func():
    """Docstring goes here."""
    print my_func.__doc__

This will work as long as you don't change the object bound to the name my_func.

new_func_name = my_func
my_func = None

new_func_name()
# doesn't print anything because my_func is None and None has no docstring

Situations in which you'd do this are rather rare, but they do happen.

However, if you write a decorator like this:

def passmein(func):
    def wrapper(*args, **kwargs):
        return func(func, *args, **kwargs)
    return wrapper

Now you can do this:

@passmein
def my_func(me):
    print me.__doc__

And this will ensure that your function gets a reference to itself (similar to self) as its first argument, so it can always get the docstring of the right function. If used on a method, the usual self becomes the second argument.