# Custom NamedTuple dynamic creation
**URL:** https://discourse.julialang.org/t/custom-namedtuple-dynamic-creation/109807
**Category:** General Usage
**Tags:** namedtuple
**Created:** [February 6, 2024, 1:59pm UTC](https://discourse.julialang.org/t/custom-namedtuple-dynamic-creation/109807 "2024-02-06T13:59:34Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@ImreMD](https://discourse.julialang.org/u/ImreMD)
#### Post date: [February 6, 2024, 1:59pm UTC](https://discourse.julialang.org/t/custom-namedtuple-dynamic-creation/109807/1 "2024-02-06T13:59:34Z")
Hello guys, wondering if there’s a way of dynamically assign keys to a NamedTuple something like this:
```julia
function create_named_tuple(x, y, z)
mynames = (:position, :y, :z)
mydata = (x, "free","get")
return NamedTuple{mynames}(mydata)
end
```
Written this way it doesn’t work the keys are literal string “y” and “z” instead of variables passed to the function. Is there a way of doing this without using additional libraries?
---
### Author:  [@rocco\_sprmnt21](https://discourse.julialang.org/u/rocco_sprmnt21)
#### Post date: [February 6, 2024, 2:57pm UTC](https://discourse.julialang.org/t/custom-namedtuple-dynamic-creation/109807/2 "2024-02-06T14:57:53Z")
see if this helps you
```julia
julia> f(y)=(;Symbol(y)=>"ypsilon",)
f (generic function with 1 method)
julia> c='c'
'c': ASCII/Unicode U+0063 (category Ll: Letter, lowercase)
julia> f(c)
(c = "ypsilon",)
julia> c='z'
'z': ASCII/Unicode U+007A (category Ll: Letter, lowercase)
julia> f(c)
(z = "ypsilon",)
```
```julia
julia> NamedTuple{(Symbol(c),)}(("ypsilon",))
(z = "ypsilon",)
```
---
### Author:  [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)
#### Post date: [February 6, 2024, 3:25pm UTC](https://discourse.julialang.org/t/custom-namedtuple-dynamic-creation/109807/3 "2024-02-06T15:25:02Z")
You could write:
```julia
function create_named_tuple(x, y, z)
mynames = (:position, Symbol(y), Symbol(z))
mydata = (x, "free", "get")
return NamedTuple{mynames}(mydata)
end
create_named_tuple("paid", "cost", "task")
```
---
### Author:  [@mikmoore](https://discourse.julialang.org/u/mikmoore)
#### Post date: [February 6, 2024, 4:06pm UTC](https://discourse.julialang.org/t/custom-namedtuple-dynamic-creation/109807/4 "2024-02-06T16:06:03Z")
Note that using dynamic keys like this may limit type stability and reduce performance in some situations. `NamedTuple` is designed with the idea that keys are usually known at compile time. You should consider whether `Dict` (which does not “compile in” they keys) is suitable for your use case.
---
### Author:  [@ImreMD](https://discourse.julialang.org/u/ImreMD)
#### Post date: [February 6, 2024, 4:35pm UTC](https://discourse.julialang.org/t/custom-namedtuple-dynamic-creation/109807/5 "2024-02-06T16:35:52Z")
> [@rafael.guerra](#):
>
> ```julia
> function create_named_tuple(x, y, z)
> mynames = (:position, Symbol(y), Symbol(z))
> mydata = (x, "free", "get")
> return NamedTuple{mynames}(mydata)
> end
>
> create_named_tuple("paid", "cost", "task")
>
> ```
Magic! Thanks. However I will take note of mikemoore remark (below) but my use case shouldn’t be so exigent on performance.
---
### Author:  [@Benny](https://discourse.julialang.org/u/Benny)
#### Post date: [February 6, 2024, 4:40pm UTC](https://discourse.julialang.org/t/custom-namedtuple-dynamic-creation/109807/6 "2024-02-06T16:40:32Z")
Hang on, are the `y` and `z` arguments not assigned to symbols to begin with? NamedTuples can only take symbols so why not constrain `y::Symbol` and `z::Symbol`? `Symbol(y)` is flexible but not everything should be forced into a symbol. A `Dict` wouldn’t need to do that to its keys.