[Python] Variables

I tried various things with Python. I've only used statically typed languages so far, so At first I was quite confused, but I think I've become able to write something at the tool level ...

Also, I struggled with the scope of variables. Differences between other global variables, class variables, and instance variables.

`test_1.py`


#!/usr/bin/env python
# coding:UTF-8

#Global variables
global_var = "global"

class Test1(object):
    #Class variables
    class_var = "class"

    def __init__(self):
        #Instance variables
        self.instance_var = "instance"

Global variables are variables handled in modules (files?) While being called global. You can call only the variable name, but when you change the contents, you need to declare as below in the function

`test_1.py`


    def global_var_test(self):
        #Global Declaration
        global gloval_var
        #Then you can change the contents
        global_var = "change"

By the way, I don't know how to call it from another module ... Well, I don't think it's like calling from another module.

I think it's a good idea to call class variables as follows.

`test_1.py`


    def get_class_var(self):
        return Test1.class_var

If you use self.class_var, it will be called as a class variable when you call it, Once assigned, the instance variable will be initialized. (If it is an instance variable once, the instance variable will be called the next time it is called.)

Therefore, it is better to fix the instance name.variable name format only to the instance variable for myself later.