> -----Original Message----- > From: Python-list > [mailto:python-list-bounces+python=deborahswanson.net@python.o > rg] On Behalf Of Gregory Ewing > Sent: Thursday, May 18, 2017 5:00 PM > To: python-list@python.org > Subject: Re: Survey: improving the Python std lib docs > > > Deborah Swanson wrote: > > > somenamedtuple._replace(kwargs) > > > > Return a new instance of the named tuple replacing specified > > fields with new values: (Examples > > box)---------------------------------------------------------------| > > | >>> > > | > > | > > | > > | >>> p = Point(x=11, y=22) > > | > > | >>> p._replace(x=33) > > | > > | Point(x=33, y=22) > > To someone who has some basic Python knowledge about what > keyword arguments are, that's actually pretty clear. What > it's saying is that any of the namedtuple's attribute names > can be used as a keyword argument to the _replace method. > > Namedtuple is something of a special case, because it doesn't > have a fixed set of acceptable keyword args. Most things do, > and there should be something somewhere in the docs > indicating what they are. Note that you may need to consult > docs for base classes to get the full picture, since e.g. > constructors often pass any keyword args they don't > understand on to their base class constructor.
I'm getting a clearer picture, and even though it might not be as cleanly straightforward as using recordsclass, I think it would be a good learning experience to use "somenamedtuple._replace(kwargs)" in a context of my own devising, rather than just copying out code given for a different problem from someone else. Besides, I need to compile memoryslots.c to make a usable recordsclass module, and I haven't successfully compiled a C program outside of Visual Studio yet(and that was a couple decades ago). So I'm going to see if I can really understand kwargs in a namedtuple context first. It will be good to have a bag of tricks to tackle all my Excel spreadsheet conversion-to-Python and new-from-scratch projects with. I'm saying goodbye to Microsoft Excel, but I want to take all my work and ideas with me. And who knows, maybe I'll have some templates and tutorials to contribute for others who'd like to do the same. > > Now, I understood what he meant from the context of the problem he was > > helping me with, but, how in the world would I have gotten that > > possible use of somenamedtuple._replace(kwargs) from the blurb and > > examples in the docs? > > From knowledge about keyword arguments in general, > exrapolation from the example, and following logic. > > I know that's probably not a very helpful answer, but the > reason it seems so obscure to you now is because you don't > have all of the basic Python knowledge that the docs assume > the reader has. If you come back to the same docs later when > you do have that knowledge, you will see it all more clearly. Oh, I think I see what you mean now. But I'm sure glad I've had this list to talk to, or I'd never have figured it out from scratch on my own. > > If there's a tutorial somewhere on kwargs in general, what specific > > types of kwargs there are, what special operators can be specifed for > > them and how the kwargs are used, it would be very helpful to have > > that tutorial referenced in a footnote-link next to kwargs whenever > > kwargs is part of a function specification. > > This is all general knowlege about the Python language that > you can't expect the reference documentation to point out in > relation to every function and method. No, perhaps not. I was frustrated by not being able to see and understand what I needed to know from the docs, but maybe more in depth tutorials for beginners, and some kind of pointers to them, would fill that gap more effectively. > > I have an item on my todo list to google "python kwargs", but it keeps > > getting pushed deeper and deeper down my list because I have so little > > hope that it will turn up anything useful. > > I strongly encourage you to do it sooner rather than later, > because you'll gain some important foundational knowledge > that's vital for understanding many things you'll see in > Python code and Python docs. > > -- > Greg I may do that Google search when I get to it, but I've learned a lot right here. Maybe enough, but Ill have to work with what I now know to see that. Thanks very much, Deborah -- https://mail.python.org/mailman/listinfo/python-list
