Should I be using "global" or "self." for class scope variables in Python?

Question

Both of these blocks of code work. Is there a "right" way to do this?

class Stuff:
    def __init__(self, x = 0):
        global globx
        globx = x
    def inc(self):
        return globx + 1

myStuff = Stuff(3)
print myStuff.inc()

Prints "4"

class Stuff:
    def __init__(self, x = 0):
        self.x = x
    def inc(self):
        return self.x + 1

myStuff = Stuff(3)
print myStuff.inc()

Also prints "4"

I'm a noob, and I'm working with a lot of variables in a class. Started wondering why I was putting "self." in front of everything in sight.

Thanks for your help!

Answer 1

You should use the second way, then every instance has a separate x

If you use a global variable then you may find you get surprising results when you have more than one instance of Stuff as changing the value of one will affect all the others.

It's normal to have explicit self's all over your Python code. If you try tricks to avoid that you will be making your code difficult to read for other Python programmers (and potentially introducing extra bugs)