[Tutor] Class definitions

[dn]

Are you training folk, or requiring in Code Reviews, the use of 
parentheses in stand-alone class definitions (or not)?


The non-responsive fellow wrote a function-definition as:

     def prnt:

(twice!) which is plainly incorrect because the def, the parentheses, 
and the colon are all compulsory [as discussed, elsewhere] - even if the 
parameter-list is empty.

     funcdef ::=  [decorators] "def" funcname [type_params] "(" 
[parameter_list] ")" ["->" expression] ":" suite

Whereas, a class-definition requires only the class and a colon. In this 
case, parentheses are only needed to delimit an inheritance argument-list.

     classdef ::=  [decorators] "class" classname [type_params] 
[inheritance] ":" suite
     inheritance ::=  "(" [argument_list] ")"

That said, and IIRC carrying-over from Python2, the inheritance 
argument-list is separately optional. In other words, one may express an 
empty set of parentheses. Accordingly, this old-timer's personal 
habit/muscle-memory(?) is to type them quite unconsciously.
- or maybe some vague-idea that they just might be needed in-future in 
the same way that we add commas after the last element of lists in case 
of later additions-and-alterations?

Conversely: over the years, I've occasionally noted newcomers becoming 
confused between function-definitions and class-definitions. Not between 
function and class as constructs, but between (function) parameter-lists 
and (class) inheritance argument-lists.

Accordingly, wondered if you feel there is virtue in writing class-names 
without parentheses, and only moving to such syntax upon reaching more 
advanced levels involving inheritance (and multiple-inheritance)?


Web.Ref:
https://docs.python.org/3/reference/compound_stmts.html
-- 
Regards,
=dn