Message 350330 - Python tracker

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Author	jdemeyer
Recipients	jdemeyer, mark.dickinson, rhettinger, serhiy.storchaka, steven.daprano
Date	2019-08-23.19:53:58
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<[email protected]>
In-reply-to

Content
> FWIW, the entire point of us having recently added as_integer_ratio() methods to so many concrete classes is to avoid the need for helper functions in favor of a simple try/except around a single call. But what about PEP 3141? The fractions.Fraction constructor accepts numbers.Rational instances, which do not necessarily have an as_integer_ratio() method. We can't just drop support for that (). So in practice you do need to check both as_integer_ratio() and the PEP 3141 numerator/denominator properties. It seems useful to have a helper function for this. () Unless you want to deprecate PEP 3141. This may be less crazy than it sounds, especially given Guido van Rossum's reaction on https://discuss.python.org/t/pep-3141-ratio-instead-of-numerator-denominator/2037/25?u=jdemeyer

> FWIW, the entire point of us having recently added as_integer_ratio() methods to so many concrete classes is to avoid the need for helper functions in favor of a simple try/except around a single call.

But what about PEP 3141? The fractions.Fraction constructor accepts numbers.Rational instances, which do not necessarily have an as_integer_ratio() method. We can't just drop support for that (*). So in practice you do need to check both as_integer_ratio() and the PEP 3141 numerator/denominator properties. It seems useful to have a helper function for this.

(*) Unless you want to deprecate PEP 3141. This may be less crazy than it sounds, especially given Guido van Rossum's reaction on https://discuss.python.org/t/pep-3141-ratio-instead-of-numerator-denominator/2037/25?u=jdemeyer

History
Date	User	Action	Args
2019-08-23 19:53:59	jdemeyer	set	recipients: + jdemeyer, rhettinger, mark.dickinson, steven.daprano, serhiy.storchaka
2019-08-23 19:53:59	jdemeyer	set	messageid: <[email protected]>
2019-08-23 19:53:59	jdemeyer	link	issue37884 messages
2019-08-23 19:53:58	jdemeyer	create