Is the @filter macro from Query.jl only useful for simple things like _.a > 1 and so on? I’ve tried to use ismissing which just returns a boolean and it does not return anything (but also does not return any errors). Broadcasting ismissing also doesn’t change the outcome (results in an error). Her…

Here is a quick check that indeed ismissing is called on a DataValue: julia> using TraceFuns julia> @trace (example |> @filter(ismissing(_.prct)) |> DataFrame) ismissing 10: ismissing(DataValue{Float64}(0.2)) -- Method ismissing(x) @ Base essentials.jl:1010 o…

There seems to be some lack of documentation: Docs for missing values · Issue #306 · queryverse/Query.jl · GitHub The docs about this: Getting Started · Query.jl Still, nobody tells us, how it is supposed to work. I tried and found that this is working, but I don’t know if it is the right way: ju…

It looks like Query.jl treats missing values as na: julia> example |> @filter(isna(_.prct)) 1x3 query result alph │ name │ prct ─────┼────────┼───── c │ carrot │ #NA

Interesting! Yes I kept rereading the doc line about the filter macro, if it returns true then the element is retained, I would not have considered doing col == True, but nice to see that something works!

So I guess by that logic none of the missing values are missing according to Query? What’s strange is that I’ve done a decent amount of manipulation on dataframes containing missing values and the instances of missing have always been retained, but perhaps that’s because by collecting back into a D…

It sounds like QueryVerse diverges from the rest of the Julia DataFrames ecosystem in some ways, to provide semantics that work with a broader set of table-like structures. One of those ways is using a replacement for missing. Unfortunately, that results in situations like this, where ismissing sile…

I think most things have been said above, but just to confirm: Union{Missing,T} columns in tables are converted to DataValue{T} inside the query, and then converted back to Union{Missing,T} if you materialize into say a DataFrame at the end. So inside the query you need to use things like isna etc. …

Thanks! I can’t really tell how to interact with DataValues.jl (even with Query loaded), so it might be beneficial for something like this to be added to the docs for Query, even if it’s as minor as a suggested replacement function for ismissing, etc. I really like the utilization of named tuples a…

Basic function usage in Query @filter

General Usage

oheil May 23, 2024, 8:14pm 4

See Query.jl - filtering on missing data

1 Like

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Basic function usage in Query @filter

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