[Tutor] OOPs and general Python questions.

[Cameron Simpson]

On 19Apr2023 18:30, mhysnm1964 at gmail.com <mhysnm1964 at gmail.com> wrote:
>What is a super class?

It is a parent class of some class.

Suppose I've got a class like this:

     class int16(int):
         ''' A subclass of int which prints in base 16.
         '''

         def __str__(self):
             return f'0x{self:x}'

This behaves just like an int except that converting it to a string 
results in a base 16 representation:

     >>> class int16(int):
     ...         def __str__(self):
     ...             return f'0x{self:x}'
     ...
     >>> i=int16(15)
     >>> i
     15
     >>> str(i)
     '0xf'
     >>> print(i)
     0xf

Here the superclass of int16 is int.

>Does python care the order of classes and methods?

Order of definition? As a dynamic language, things are defined by 
executing them. So they happen in the order they're in the file. That 
means that if defining B requires use of A, then A needs to have been 
defined by the time you go to define B.

     class A:
         def method(self, x):
             print("A:", x)

     class B(A):
         def method(self, x):
             print("B:", x)

Here, the class A needs to be defined in order to define the class B, 
because B subclasses A. Swapping them around won't work. try it!

It is no different to this:

     x = 1
     y = x * 2

You can't swap these around either, for exactly the same reason.

Cheers,
Cameron Simpson <cs at cskk.id.au>