DM-31535: Deprecate default-position-argument interface to Psf methods.

[jmeyers314]

No description provided.

[ktlim]

I'm pretty sure you don't need or want this. This file is only used for its side effects.

[ktlim]

If this is going to show up too frequently, I think it is possible to wrap these differently and explicitly issue a warning only on the bad overload. It's a bit complex, though, which is why the Dev Guide doesn't mention it, and it may not be worth it.

[jmeyers314]

How would you suggest this work? My thought was to use a lambda when binding to manually emit a warning before passing through to the wrapped method. Maybe there's a way to do this just within python though?

[ktlim]

Here's an example of how this was done in the past using a Python-only patch: 488744f#diff-3428060cb78fe305ebd4f720718710a2421cc76d4b355393edb26ab6a74ce0d0

[jmeyers314]

Sure, I considered inspecting the args like this but decided against it since it doesn't accomplish the sphinx decoration that deprecate_pybind11 does.

[jmeyers314]

But if we're okay with ignoring the sphinx docs mangling, I think I'd prefer doing the same thing without the argument inspection; i.e., in _psf.cc something like:

                // cls.def("computeImage", py::overload_cast<>(&Psf::computeImage, py::const_));
                cls.def("computeImage",
                        [](const Psf& psf) {
                            auto warnings = py::module::import("warnings");
                            auto builtins = py::handle(PyEval_GetBuiltins());
                            auto FutureWarning = builtins["FutureWarning"];
                            warnings.attr("warn")(
                                "This is the warning",
                                "category"_a=FutureWarning,
                                "stacklevel"_a=2
                            );
                            return psf.computeImage();
                        }
                );

I assume there's a way to make this into a template too, though that might be a bit beyond my skillset.

[ktlim]

Any of the three options is OK with me: deprecate_pybind11, warn in Python, warn in the wrapper.