I am a beginner and need consult

def function_outside():
    return "outside"

class Function:
    
    f_o = function_outside()

    def function_inside():
        return "inside"

print (Function.f_o)
print (Function.function_inside())

If we observe the aforementioned code, why is it a necessity to store the outside-class-function inside an instance variable? Can't we use the global keyword to make the outside-class-function accessible from inside the class? And if we do that, then our first few lines of the code would look like:

def function_outside():
    return "outside"

class Function:

    global function_outside()

But the code gives a syntax error. I need help :(