[Python-ideas] Re: Passing Arguments Through Thin Wrappers (was : Auto-assign attributes from __init__ arguments)
>from inspect import stack, Signature > >def parameters(): >caller = stack()[2][0].f_globals[stack()[1][3]] >sig = Signature.from_callable(caller) >vars = stack()[1][0].f_locals >return sig.bind(**vars).arguments This also doesn't work for me if a variable is assigned inside the function before parameters() is called. Although I know you weren't suggesting this was a final working version, it does at least illustrate that this isn't a trivial problem to solve. Whilst this is slightly different from my idea of having a function to set the class attributes based on the parameters to init, having something like parameters() would reduce this to a one-liner, and I'd definitely find it useful for passing to super, which has been mentioned already. Lewis On Tue, 5 May 2020, 16:18 Barry Scott, wrote: > > > > On 5 May 2020, at 15:38, Steven D'Aprano wrote: > > > > Here is a quick and dirty proof of concept: > > > > > >from inspect import stack, Signature > > > >def parameters(): > >caller = stack()[2][0].f_globals[stack()[1][3]] > >sig = Signature.from_callable(caller) > >vars = stack()[1][0].f_locals > >return sig.bind(**vars).arguments > > > > > >def func(spam, eggs): > >params = parameters() > >for name, value in params.items(): > >print(name, '=', value) > > > > > > Calling `func(2, 3)` prints: > > > >spam = 2 > >eggs = 3 > > Is this to avoid locals()? > > Do you have a version that works inside a func of a class? > > I tried the obvious and it TB'ed: > > > from inspect import stack, Signature > > def parameters(): > caller = stack()[2][0].f_globals[stack()[1][3]] > sig = Signature.from_callable(caller) > vars = stack()[1][0].f_locals > return sig.bind(**vars).arguments > > > class X: > > def func(self, spam, eggs): > params = parameters() > for name, value in params.items(): > print(name, '=', value) > > x = X() > x.func( 1, 2 ) > > Traceback (most recent call last): > File "args.py", line 25, in > x.func( 1, 2 ) > File "args.py", line 20, in func > params = parameters() > File "args.py", line 11, in parameters > caller = stack()[2][0].f_globals[stack()[1][3]] > KeyError: 'func' > > > Barry > > > > > > > -- > > Steven > > ___ > > Python-ideas mailing list -- python-ideas@python.org > > To unsubscribe send an email to python-ideas-le...@python.org > > https://mail.python.org/mailman3/lists/python-ideas.python.org/ > > Message archived at > https://mail.python.org/archives/list/python-ideas@python.org/message/62ZDUVMEKQEMBRTVHM2GYXZVJLPPHYBQ/ > > Code of Conduct: http://python.org/psf/codeofconduct/ > > > ___ > Python-ideas mailing list -- python-ideas@python.org > To unsubscribe send an email to python-ideas-le...@python.org > https://mail.python.org/mailman3/lists/python-ideas.python.org/ > Message archived at > https://mail.python.org/archives/list/python-ideas@python.org/message/7BVSYMV4Q7SOOEGC5UDLMWVZ6XT5RVUY/ > Code of Conduct: http://python.org/psf/codeofconduct/ > ___ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/J6BMZISIMHTUFD47S7XFCTEXLALF7AOM/ Code of Conduct: http://python.org/psf/codeofconduct/
[Python-ideas] Re: Passing Arguments Through Thin Wrappers (was : Auto-assign attributes from __init__ arguments)
> On 5 May 2020, at 15:38, Steven D'Aprano wrote: > > Here is a quick and dirty proof of concept: > > >from inspect import stack, Signature > >def parameters(): >caller = stack()[2][0].f_globals[stack()[1][3]] >sig = Signature.from_callable(caller) >vars = stack()[1][0].f_locals >return sig.bind(**vars).arguments > > >def func(spam, eggs): >params = parameters() >for name, value in params.items(): >print(name, '=', value) > > > Calling `func(2, 3)` prints: > >spam = 2 >eggs = 3 Is this to avoid locals()? Do you have a version that works inside a func of a class? I tried the obvious and it TB'ed: from inspect import stack, Signature def parameters(): caller = stack()[2][0].f_globals[stack()[1][3]] sig = Signature.from_callable(caller) vars = stack()[1][0].f_locals return sig.bind(**vars).arguments class X: def func(self, spam, eggs): params = parameters() for name, value in params.items(): print(name, '=', value) x = X() x.func( 1, 2 ) Traceback (most recent call last): File "args.py", line 25, in x.func( 1, 2 ) File "args.py", line 20, in func params = parameters() File "args.py", line 11, in parameters caller = stack()[2][0].f_globals[stack()[1][3]] KeyError: 'func' Barry > > > -- > Steven > ___ > Python-ideas mailing list -- python-ideas@python.org > To unsubscribe send an email to python-ideas-le...@python.org > https://mail.python.org/mailman3/lists/python-ideas.python.org/ > Message archived at > https://mail.python.org/archives/list/python-ideas@python.org/message/62ZDUVMEKQEMBRTVHM2GYXZVJLPPHYBQ/ > Code of Conduct: http://python.org/psf/codeofconduct/ > ___ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/7BVSYMV4Q7SOOEGC5UDLMWVZ6XT5RVUY/ Code of Conduct: http://python.org/psf/codeofconduct/
[Python-ideas] Re: Passing Arguments Through Thin Wrappers (was : Auto-assign attributes from __init__ arguments)
On 05.05.20 15:35, Dan Sommers wrote: On Tue, 5 May 2020 23:06:39 +1000 Steven D'Aprano wrote: ... help me solve the DRY problem for module-level functions: def function(spam, eggs, cheese, aardvark): do stuff call _private_function(spam, eggs, cheese, aardvark) since this bites me about twice as often as the `self.spam = spam` issue. (That's not me being snarky by the way, it's a genuine question: dataclasses are a mystery to me, so I don't know what they can and can't do.) Lisp macros have a "" feature that captures the entire collection of arguments to the macro: http://clhs.lisp.se/Body/03_dd.htm Perhaps Python could adopt something similar? Unlike *args and **kwargs, captures all of the parameters, not just the non-positional, non-named ones. The idea would be something like this: def function(spam, eggs, cheese, aardvark, ): do_stuff _private_function() which would call _private_function as function was called. What about a way for overloading function signatures? The arguments are then bound to both signatures and the function has access to all the parameters. For example: def function(spam, eggs, cheese, aardvark) with (*args): ... # do stuff _private_function(*args) Calling `function(1, 2, 3, 4)` results in `spam, eggs, cheese, aardvark = 1, 2, 3, 4` and `args = (1, 2, 3, 4)`. ___ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/OHGIK5YHET6YUANFDT7RRXRT47AIAYM5/ Code of Conduct: http://python.org/psf/codeofconduct/
[Python-ideas] Re: Passing Arguments Through Thin Wrappers (was : Auto-assign attributes from __init__ arguments)
Here is a quick and dirty proof of concept: from inspect import stack, Signature def parameters(): caller = stack()[2][0].f_globals[stack()[1][3]] sig = Signature.from_callable(caller) vars = stack()[1][0].f_locals return sig.bind(**vars).arguments def func(spam, eggs): params = parameters() for name, value in params.items(): print(name, '=', value) Calling `func(2, 3)` prints: spam = 2 eggs = 3 -- Steven ___ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/62ZDUVMEKQEMBRTVHM2GYXZVJLPPHYBQ/ Code of Conduct: http://python.org/psf/codeofconduct/
