Feature Request: accept NamedTuple as attrib ?

[ryofurue]

Describe the problem

NCDatasets v0.13.1

I've been finding OrderedDict( . . .) a bit too bulky and also you have to always use OrderedCollections, and so I use Dict instead as I don't care about the order of the attributes. But Dict is still a bit bulky including the fact you have to quote the name of the attribute. I would think that NamedTuple is ideally suited for attributes:

defVar(ds,...,attrib=(units="m/s", _FillValue=NaN))

Because we wouldn't have thousands of attributes, we don't need the performance of Dict. (If anything, I guess that NamedTuple is a bit more performant for a small number of attributes. Not that performance matters, though.)

(But, looking at the error message when I used a NamedTuple, I guess I should request OrderedDict to be able to be initialized with a NamedTuple?)

[As an aside, it would also be nice if Dict(:units => "m/s") be accepted. Your IDE will color a Symbol differently from a String, which makes the key-value pair more readable (unless you have a Symbol value :-). ]

[Alexander-Barth]

Yes, I agree. This is a good idea.

It is implemented in JuliaGeo/CommonDataModel.jl@6eb7d80

The following code should work now with the main branch:

# NCDatasets issue #241

filename = tempname()
ds = NCDataset(filename,"c")
data = randn(4,5)

defVar(ds,"temperature",data,("lon","lat"),
       attrib = OrderedDict(:long_name => "Temperature",
                 :test_vector_attrib => [1,2,3]))

defVar(ds,:temperature2,data,(:lon,:lat),
       attrib = OrderedDict(:long_name => "Temperature",
                 :test_vector_attrib => [1,2,3]))


defVar(ds,:temperature3,data,(:lon,:lat),
       attrib = Dict(:long_name => "Temperature",
                 :test_vector_attrib => [1,2,3]))

defVar(ds,:temperature4,data,(:lon,:lat),
       attrib = (long_name = "Temperature",
                 test_vector_attrib = [1,2,3]))

for (vn,var) in ds
    @test startswith(vn,"temperature")
    @test var.attrib["long_name"] == "Temperature"
    @test var.attrib["test_vector_attrib"] == [1,2,3]
end

[Alexander-Barth]

closing as completed.