Is there are good DRY fix for this painful design pattern?

[MRAB]

On 2018-02-26 21:12, Rick Johnson wrote:
> On Monday, February 26, 2018 at 8:44:14 AM UTC-6, Steven D'Aprano wrote:
>> I have a class with a large number of parameters (about
>> ten) assigned in `__init__`. The class then has a number of
>> methods which accept *optional* arguments with the same
>> names as the constructor/initialiser parameters. If those
>> arguments are None, the defaults are taken from the
>> instance attributes.
>>
>> An example might be something like this:
>>
>> class Foo:
>>     def __init__(self, bashful, doc, dopey, grumpy,
>>                        happy, sleepy, sneezy):
>>         self.bashful = bashful  # etc
>>
>>     def spam(self, bashful=None, doc=None, dopey=None,
>>                    grumpy=None, happy=None, sleepy=None,
>>                    sneezy=None):
>>         if bashful is None:
>>             bashful = self.bashful
>>         if doc is None:
>>             doc = self.doc
>>         if dopey is None:
>>             dopey = self.dopey
>>         if grumpy is None:
>>             grumpy = self.grumpy
>>         if happy is None:
>>             happy = self.happy
>>         if sleepy is None:
>>             sleepy = self.sleepy
>>         if sneezy is None:
>>             sneezy = self.sneezy
>>         # now do the real work...
>>
>>     def eggs(self, bashful=None, # etc...
>>                    ):
>>         if bashful is None:
>>             bashful = self.bashful
>>         # and so on
> 
> 
> Steven... even if this example code is absolutely atrocious
> (because it is!), and even *IF* i have a uneasy suspicion
> that this "inquiry" masks some dastardly malicious plan
> (because i do!), I must admit, I am happy to see that you
> are _finally_ embracing the OOP paradigm.
> 
> For starters, I would suggest replacing those ugly if-
> clauses with some short-circuit or'd-logic. But obviously
> you need to run that "paragraph of arguments" through a
> single helper function, as the point of "DRY" is "Don't
> Repeat Yourself".
> 
Before using or'd-logic, you need to know whether the value could be 
falsey, e.g. 0.

> </pesos count="2">
>