to be pythonic: should caller or callee log?

[Xaxa Urtiz]

Le mercredi 4 septembre 2013 09:44:27 UTC+2, Gildor Oronar a écrit :
> Thanks:
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> 
> 
> El 04/09/13 05:01, Terry Reedy escribió:
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> 
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> > I would expect that every account class has a transaction method.
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> > * If so, just call it, but
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> > assertIsNot(DebitAccount.transaction, AbstractAccount.transaction)
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> > for every subclass in your test suite.
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> > * If not, perhaps you need an abstract subclass TransAccount. Then use
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> > hasattr in production code and the isnot test in test code.
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> 
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> I would assume that you categorize this as a unit test problem, because 
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> you consider an Acount not implementing Transaction is a bug, right?
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> 
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> There are two occassions an account is intended not having Transaction 
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> function, both not test-related:
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> 
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> 1. The acount doesn't offer this feature. e.g. Certificate of Deposit. 
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> This can be in TransAccount.
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> 
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> 2. The 3rd-party account offer this feature but doesn't qualify the 
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> software's requirement, e.g. not returning the result in 3 seconds, and 
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> is avoided when planning the deal (I am writing an auto-trade software). 
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> This case you cannot categorize those who can into TransAccount, 
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> beacause 1) that naming imply other accounts don't do transaction but 
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> they do, just not good enough; 2) when other accounts becomes good 
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> enough, the change (to inheritance) is a bit too invasive.

Hello,
and what about something like that :


class AbsctractAccount():
     def transaction(self, amount, target):
         logging.info("Start transaction of %s to %s" % (amount, target))
         self.DoTransaction(amount,target)

     def DoTransaction(self,amount,target):
         pass # or raise notimplemented or do not implement this methods in the abstract class
         ...

class DebitAccount(AbstractAccount):
     def DoTransaction(self, amount, target):
         ...

class SomeOtherAccount(...)
     .... 
like that you only have to write the logging function once.