@@wonderfulworld1128 functions can be passed as arguments to other functions and references to their heap definitions are what get passed around (in Python). There's nothing special about the main function in Python, you can write it to return values of you'd like.

@@KrisJordan sir your mean to say that whenever a function def encounterd in python script python holds the name in global stack frame and it's reference is hold in the heap memory... Whenever a function is called in script a new call stake frame initialzed in stake memory and all its variables and values stores in that particular frame. My question is that when this function returning a value let say 4(immutable type) or any function inside (not been called yet), the value has to be gone to the the caller end.. and reference has been hold by the any variable let say num_result... but the return value where gone in the stack memory or heap memory?? And also the function we'd returned the definition of insided , where it gone?? Because I know whenever return statement encountered call stacks is removed and the reference it hold in heap it's all gonna be removed..sir please give me some examples to understand what's going in memory when all of this kind stuffs happens in code?? As you shared in this video like that, I would be very happy to learn something in detail???

It think it is called a "Unit of compilation" the linker will connect all public (non static) symbols.