Object attribute

[Uchikago]

Hi, i'm just a new beginer, so please help me! Today i've come across this syntax module.attribute, i'm wondering what this use for ? And it's syntax looks like when we call method such as list.append(4),are both of them related to each other ? And i've seen some functions like this:

def func():
    func.a=2

why we have to put a func before a, why don't we just write a=2 does it make any difference ?