# Query.jl v0.9.x released

**URL:** <https://discourse.julialang.org/t/query-jl-v0-9-x-released/7885>\
**Category:** Community\
**Created:** [December 20, 2017, 6:12pm UTC](https://discourse.julialang.org/t/query-jl-v0-9-x-released/7885 "2017-12-20T18:12:15Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![davidanthoff](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/davidanthoff/32/223493_2.png) [@davidanthoff](https://discourse.julialang.org/u/davidanthoff)\
**Post date:** [December 20, 2017, 6:12pm UTC](https://discourse.julialang.org/t/query-jl-v0-9-x-released/7885/1 "2017-12-20T18:12:15Z")

</div>

I just released [Query.jl](https://github.com/davidanthoff/Query.jl) v0.9.0. The new version adds the `@take` and `@drop` standalone query operators and brings pretty printing to uncollected queries.

# Pretty printing

In previous versions queries displayed a really awful mess of internal data when they were displayed in the REPL. In practice one always had to collect a query into something like a `DataFrame` to get a nice view of the query result. The new version changes that and provides a nice output for any query, even an uncollected one. Here is an example:

```julia
julia> using FileIO, Query, CSVFiles

julia> filename = "https://gist.githubusercontent.com/davidanthoff/bebfd24c1a3f32f576eb61bee77f5944/raw/dd9233ad860037a2155f3a9ca3c37eb2d5572573/testdata2.csv";

julia> load(filename) |> @map({_.Year, _.Cause_Name})
15028x2 query result
Year │ Cause_Name
─────┼───────────────────────
1999 │ Unintentional Injuries
1999 │ Unintentional Injuries
1999 │ Unintentional Injuries
1999 │ Unintentional Injuries
1999 │ Unintentional Injuries
1999 │ Unintentional Injuries
1999 │ Unintentional Injuries
1999 │ Unintentional Injuries
1999 │ Unintentional Injuries
1999 │ Unintentional Injuries
... with 15018 more rows

```

The pretty printing should work for the values returned from any of the query operators. The output format is heavily inspired by R’s tibbles.

I hope this will make interactive work much more pleasant because it should be easier to build up more complicated queries step by step, while periodically running a query to check intermediate results.

I also plan to add this to the whole tabular file IO of the iterable tables ecosystem at a later date (e.g. [CSVFiles.jl](https://github.com/davidanthoff/CSVFiles.jl), [FeatherFiles.jl](https://github.com/davidanthoff/FeatherFiles.jl), [ExcelFiles.jl](https://github.com/davidanthoff/ExcelFiles.jl), [StatFiles.jl](https://github.com/davidanthoff/StatFiles.jl) etc.).

# The `@take` and `@drop` query commands

Those are fairly straightforward: both of these filter elements out of a sequence. `@take` limits the number of elements to some upper maximum, and `@drop` skips a number of elements. Here is an example of how one can use these:

```julia
using FileIO, Query, CSVFiles

filename = "https://gist.githubusercontent.com/davidanthoff/bebfd24c1a3f32f576eb61bee77f5944/raw/dd9233ad860037a2155f3a9ca3c37eb2d5572573/testdata2.csv"

load(filename) |> 
    @filter(_.Cause_Name!="All Causes" && !isnull(_.Age_adjusted_Death_Rate)) |> 
    @groupby(_.Cause_Name) |> 
    @map({cause=_.key, death_rate=sum(_..Age_adjusted_Death_Rate)}) |>
    @orderby_descending(_.death_rate) |> 
    @drop(2) |> 
    @take(3) |>
    save("output.feather")

```

This example showcases a whole range of features, including the use of the `@drop` and `@take` operations. The official documentation for these two new operators is in the “Experimental Features” section in the [Query.jl](https://github.com/davidanthoff/Query.jl) [documentation](http://www.david-anthoff.com/Query.jl/stable/)

Any feedback on these new features (and old ones) is most welcome, and of course any help with the overall package would also be fantastic!