The wrapt module I linked to (not funtools.wraps) provides all the capabilities you mention since 2013. It allows mixed use of decorators as decorator factories. It has a flat style.
There are some minor API difference between your libraries and wrapt, but the concept is very similar. Since yours is something new, I imagine you perceive some win over what wrapt does. On Tue, Mar 12, 2019, 9:52 AM Sylvain MARIE <sylvain.ma...@se.com> wrote: > David, Steven, > > Thanks for your interest ! > > As you probably know, decorators and function wrappers are *completely > different concepts*. A decorator can directly return the decorated function > (or class), it does not have to return a wrapper. Even more, it can > entirely replace the decorated item with something else (not even a > function or class!). Try it: it is possible to write a decorator to replace > a function with an integer, even though it is probably not quite useful :) > > `decopatch` helps you write decorators, whatever they are. It "just" > solves the annoying issue of having to handle the no-parenthesis and > with-parenthesis calls. In addition as a 'goodie', it proposes two > development styles: *nested* (you have to return a function) and *flat* > (you directly write what will happen when the decorator is applied to > something). > -- > Now about creating signature-preserving function wrappers (in a decorator, > or outside a decorator - again, that's not related). That use case is > supposed to be covered by functools.wrapt. Unfortunately as explained here > https://stackoverflow.com/questions/308999/what-does-functools-wraps-do/55102697#55102697 > this is not the case because with functools.wrapt: > - the wrapper code will execute even when the provided arguments are > invalid. > - the wrapper code cannot easily access an argument using its name, from > the received *args, **kwargs. Indeed one would have to handle all cases > (positional, keyword, default) and therefore to use something like > Signature.bind(). > > For this reason I proposed a replacement in `makefun`: > https://smarie.github.io/python-makefun/#signature-preserving-function-wrappers > -- > Now bridging the gap. Of course a very interesting use cases for > decorators is to create decorators that create a signature-preserving > wrapper. It is possible to combine decopatch and makefun for this: > https://smarie.github.io/python-decopatch/#3-creating-function-wrappers . > Decopatch even proposes a "double-flat" development style where you > directly write the wrapper body, as explained in the doc. > > Did I answer your questions ? > Thanks again for the quick feedback ! > Best, > > Sylvain > > -----Message d'origine----- > De : Python-ideas <python-ideas-bounces+sylvain.marie=se....@python.org> > De la part de Steven D'Aprano > Envoyé : mardi 12 mars 2019 12:30 > À : python-ideas@python.org > Objet : Re: [Python-ideas] Problems (and solutions?) in writing decorators > > [External email: Use caution with links and attachments] > > ________________________________ > > > > On Tue, Mar 12, 2019 at 09:36:41AM +0000, Sylvain MARIE via Python-ideas > wrote: > > > I therefore proposed > > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsma > > rie.github.io%2Fpython-makefun%2F&data=02%7C01%7Csylvain.marie%40s > > e.com%7C579232e7e10e475314c708d6a6de9d23%7C6e51e1adc54b4b39b5980ffe9ae > > 68fef%7C0%7C0%7C636879872385158085&sdata=nB9p9V%2BJ7gk%2Fsc%2BA5%2 > > Fekk35bnYGvmEFJyCXaLDyLm9I%3D&reserved=0 . In particular it > > provides an equivalent of `@functools.wraps` that is truly > > signature-preserving > > Tell us more about that please. I'm very interested in getting decorators > preserve the original signature. > > > -- > Steven > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmail.python.org%2Fmailman%2Flistinfo%2Fpython-ideas&data=02%7C01%7Csylvain.marie%40se.com%7C579232e7e10e475314c708d6a6de9d23%7C6e51e1adc54b4b39b5980ffe9ae68fef%7C0%7C0%7C636879872385158085&sdata=XcYfEginmDF7kIpGGA0XxDZKpUn9e4p2zPFk7UAruYg%3D&reserved=0 > Code of Conduct: > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpython.org%2Fpsf%2Fcodeofconduct%2F&data=02%7C01%7Csylvain.marie%40se.com%7C579232e7e10e475314c708d6a6de9d23%7C6e51e1adc54b4b39b5980ffe9ae68fef%7C0%7C0%7C636879872385158085&sdata=20ZrtVQZbpQ54c96veSXIOfEK7rKy0ggj0omTZg3ri8%3D&reserved=0 > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > ______________________________________________________________________ >
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