Empty Named Tuple

General Usage
1

Is it possible to initialize an empty NamedTuple with the appropriate keys and types for values? Can you then push future NamedTuples into this empty NamedTuple?

Thanks!

2

Nope. part of the reasons named tuples are so useful is that they are immutable. You probably want to use a Dict if this is your use case. the package NamedTupleTools might have something you are interested in.

If you have a Dict d where all the keys are Symbols, you can do

NamedTuple{Tuple(keys(d))}(Tuple(values(d)))
3

You can’t mutate named tuples in-place. Some idioms that can be helpful here:

julia> a = NamedTuple()
NamedTuple()

julia> a = (;)  # doesn't work in old Julia releases
NamedTuple()

julia> a = merge(a, (x=1,))
(x = 1,)

julia> a = (; a..., y=2)
(x = 1, y = 2)

julia> a = (; a..., :z => 3)
(x = 1, y = 2, z = 3)

julia> d = Dict(:aaa => 1, :bbb => 2, :ccc => 3);

julia> (; d...)
(bbb = 2, ccc = 3, aaa = 1)
5 Likes
4

Thanks. I am trying to learn how to utilize tuples for performance.

5

Thanks this was helpful.