[Twisted-Python] 3 basic questions about connectionLost, reactor stop and design
andrew-twisted at puzzling.org
Mon Apr 2 08:58:08 EDT 2007
> Finally, my question is why twisted use class attribute so widely? Is
> there any benefit? In my opinion, __init__ function is the only good
> place to define 'attributes'. But
> twist distributes 'attributes' in two forms: class and __init__. I
> want to know the idiom to decide which attribute should be put into
> which part.
No particular reason, but here are some small reasons for using class
* their presence (and initial value) is visible in the declaration of the
class, rather than requiring reading the code of the __init__ method;
* as a result, the variables (and initial values) will be automatically
listed by tools like epydoc and pydoctor (if the author forgets to
explicitly describe these attributes in the docstrings);
* they require less typing from the code author than an assignment to
"self.foo" in __init__;
* if the class doesn't have an __init__ method yet, it saves even more typing
to use a class variable than to add an __init__ just to set an instance
* they slightly reduce memory consumption.
I'm not sure these reasons are good enough to compensate for the confusion this
idiom can cause, but they're the ones I can think of. I suspect in Twisted's
case the main reasons are the "less typing" ones rather than anything else.
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