How can I do %lprun work on nested function in python?

Question

In jupyter Notebook, I am trying to use %lprun on nested functions but I do not sucess.

The following code, in a notebook cell

def outerfoo():
    def innerfoo():
        print("Hello World")
        print("Good Bye")
    innerfoo()

%lprun -f outerfoo().innerfoo outerfoo()

outputs the messages (Hello World and GoodBye) but after I have this error :
UsageError: Could not find function 'outerfoo().innerfoo'.
AttributeError: 'NoneType' object has no attribute 'innerfoo'

And this one,

def outerfoo():
    def innerfoo():
        print("Hello World")
        print("Good Bye")
    %lprun -f innerfoo innerfoo()


outerfoo()

does not print messages and gives this error :
UsageError: Could not find function 'innerfoo'. NameError: name 'innerfoo' is not defined

How is it possible to profile innerfoo ?

Answer 1

I don't think you can use notebook magic inside of actual Python code, so using %lprun inside of a function block will likely never work. Instead you can store a global reference to your local function, then lprun that:

ref = None
def outerfoo():
    global ref
    def innerfoo():
        print("Hello World")
        print("Good Bye")
    innerfoo()
    ref = innerfoo

# Must be called for `ref` to exist.
outerfoo()

%lprun -f ref ref()

But all of this feels very icky. You probably shouldn't be creating nested functions in the first place.