When *don't* I use 'self' in classes?

[MRAB]

Adam Gaskins wrote:
> I am a bit confused as too when, if ever, it is not appropriate to prepend 
> 'self' to objects in a class. All of the examples of how to use 'self' that 
> I find seem to be short and very simple (as examples tent to be). I 
> appologize if I am asking an ignorant question here, but I want to get off 
> on the right foot. Here's an example of what I mean:
> 
> import serial
> class foo:
>     def __init(self, comport):
           ^^^^^^
           Should be '__init__'.

>         self.comport = comport
>         self.baudrate = 9600 #default
>         self.ser = serial
>         try:
>             self.ser.Serial()
>             self.ser.baudrate = self.baudrate
>             self.ser.open()
>         except:
>             print 'Serial port could not be opened'
> 
> === OR ===
> import serial
> class foo:
>     def __init(self, comport):
>         self.comport = comport
>         self.baudrate = 9600 #default
>         try:
>             ser = serial.Serial()
>             ser.baudrate = self.baudrate
>             ser.open()
>         except:
>             print 'Serial port could not be opened'
> 
> There may be a typo in here, this is just a random example similar to 
> something I'm working with, but which one of these are more 'proper'? If I 
> am importing a library do I still prepend it's object with self when I use 
> it in my class? I suppose my question is just basically... when do you NOT 
> prepent an object in a class with 'self'?
> 
> I'm not even sure I'm using the term 'object' correctly here. Feel free to 
> set me straight, but I hope my example makes it clear what I am asking.
> 
> Thanks a lot, this ng has already been super helpful as I take my 
> crash-course in to python! :P 
> 
In the second example 'ser' is just a local variable within '__init__'.