Introspecting a given function's nested (local) functions in Python

Question

Given the function

def f():
    x, y = 1, 2 
    def get():
        print 'get'
    def post():
        print 'post'

is there a way for me to access its local get() and post() functions in a way that I can call them? I'm looking for a function that will work like so with the function f() defined above:

>>> get, post = get_local_functions(f)
>>> get()
'get'

I can access the code objects for those local functions like so

import inspect
for c in f.func_code.co_consts:
    if inspect.iscode(c):
        print c.co_name, c

which results in

get <code object get at 0x26e78 ...>
post <code object post at 0x269f8 ...>

but I can't figure out how to get the actual callable function objects. Is that even possible?

Thanks for your help,

Will.

Answer 1

You are pretty close of doing that - just missing new module:

import inspect
import new

def f():
    x, y = 1, 2
    def get():
        print 'get'
    def post():
        print 'post'

for c in f.func_code.co_consts:
    if inspect.iscode(c):
        f = new.function(c, globals())
        print f # Here you have your function :].

But why the heck bother? Isn't it easier to use class? Instantiation looks like a function call anyway.

Answer 2

You can return functions just like any other object in Python:

def f():
    x, y = 1, 2 
    def get():
        print 'get'
    def post():
        print 'post'
    return (get, post)


get, post = f()

Hope this helps!

Note, though, that if you want to use your 'x' and 'y' variables in get() or post(), you should make them a list.

If you do something like this:

def f():
    x = [1]
    def get():
        print 'get', x[0]
        x[0] -= 1
    def post():
        print 'post', x[0]
        x[0] += 1
    return (get, post)

get1, post1 = f()
get2, post2 = f()

get1 and post1 will reference a different 'x' list than get2 and post2.