What's the best way to minimize the need of run time checks?

[BartC]

On 13/08/2016 13:08, BartC wrote:
> On 13/08/2016 12:10, Chris Angelico wrote:
>> On Sat, Aug 13, 2016 at 8:09 PM, BartC <bc at freeuk.com> wrote:
>
>> And if subclassing isn't enough, there's no end of stuff you can do
>> with decorators. Try this:
>>
>> class Foo:
>>     @prop
>>     class demo:
>>         """Declarative property"""
>>         def get(self):
>>             print("Getting %s.demo" % self)
>>             return 42
>>         def set(self, val):
>>             print("Setting %s.demo" % self)
>>         def delete(self):
>>             print("Deleting %s.demo" % self)
>>
>> Yaknow, because @property is just waaaaaaay too clunky, right? :) But
>> I needed a simple demo. The decorator isn't even all that complicated.
>>
>> def prop(cls):
>>     return property(cls.get, getattr(cls, "set"), getattr(cls,
>> "delete"), cls.__doc__)

> (But don't try and explain decorators. I've tried several times to get
> my head around them.)

This is a clearer than usual explanation:

  http://thecodeship.com/patterns/guide-to-python-function-decorators/

Not quite simple enough however to figure out how decorators benefit 
your example! (Maybe an example with and without decorators?)

So if the aim is to keep code readable and understandable to as wide an 
audience as possible, 'decorators' don't really work. (Perhaps if they 
are buried somewhere else and only an interface is visible, but then it 
doesn't matter so much how hairy that buried code is.)

-- 
Bartc