I prefer to use clickhouse-local for all my CSV needs as I don't need to learn a new language (or cli flags) and can just leverage SQL.

    clickhouse local --file medias.csv --query "SELECT edito, count() AS count from table group by all order by count FORMAT PrettyCompact"

   ┌─edito──────┬─count─┐
   │ agence     │     1 │
   │ agrégateur │    10 │
   │ plateforme │    14 │
   │ individu   │    30 │
   │ media      │   423 │
   └────────────┴───────┘

With clickhouse-local, I can do lot more as I can leverage full power of clickhouse.

  clickhouse local
  ClickHouse local version 25.4.1.1143 (official build).

  :)

  clickhouse local --query "SELECT count() FROM file('top-1m-2018-01-10.csv.zip :: *.csv')"
  1000000

Can't help but thinking how handy PowerShell is out of the box for tasks like this.

Translating the examples from the ReadMe, having read the file with:

  $medias = Get-Content .\medias.csv | ConvertFrom-Csv

Previewing the file in the terminal

  xan view medias.csv
  $medias | Format-Table

Reading a flattened representation of the first row

  xan flatten -c medias.csv
  $medias | Format-List

Searching for rows

  xan search -s outreach internationale medias.csv | xan view
  $medias | Where-Object { $_.outreach -eq "internationale" } | Format-Table

Selecting some columns

  xan select foundation_year,name medias.csv | xan view
  $medias | Select-Object -Property foundation_year, name | Format-Table

Sorting the file

  xan sort -s foundation_year medias.csv | xan view -s name,foundation_year
  $medias | Sort-Object -Property foundation_year | Select-Object -Property name, foundation_year | Format-Table

Deduplicating the file on some column

  # Some medias of our corpus have the same ids on mediacloud.org
  xan dedup -s mediacloud_ids medias.csv | xan count && xan count medias.csv
  $medias | Select-Object -ExpandProperty mediacloud_ids -Unique | Measure-Object; $medias | Measure-Object -Property mediacloud_ids

Computing frequency tables

  xan frequency -s edito medias.csv | xan view
  $medias | Group-Object -Property edito | Sort-Object -Property Count -Descending

It's probably orders of magnitude slower, and of course, plotting graphs and so on gets tricky. But for the simple type of analysis I typically do, it's fast enough, I don't need to learn an extra tool, and the auto-completion of column/property names is very convenient.

    $medias = open .\medias.csv

    let $medias = http get https://github.com/medialab/corpora/raw/master/polarisation/medias.csv
    $medias

    $medias | columns

   $medias | length

    $medias | each {print $in}

    $medias | where $it.outreach == 'internationale'

    $medias | select foundation_year name

    $medias | select foundation_year name | sort-by foundation_year

    $medias | uniq-by mediacloud_ids

    $medias | histogram edito

I was going to mention BurntSushis excellent xsv, also written in rust ... but I see xan mantions its a fork + rewrite of xsv.

I use Pandas for most of my CSV work. It's super fast and very powerful. There's a bit of a learning curve. I can then use Python scripts to manipulate massive CSV files.

I tend to use csvkit for more complicated transformations, and OCaml's csvtool[0] for the simpler ones. For intermediate transformations I wrote my own csved[1] script, which reads for every line of a CSV reads it into @F, applies a Perl expression to that array, then writes it out. With the -h option you can also use the %F hash to access fields by name. It's very fast.

It looks like xsv and xan are in the "csvkit but faster" niche, which is nice, but now I must learn another set of commands.

And there are now many more recent utilities called csvtool, including a Perl and a Python one.

[0] https://github.com/Chris00/ocaml-csv

[1] https://github.com/gpvos/csved

People will do anything to avoid learning SQL.

I recently came across miller (https://github.com/johnkerl/miller). I don't know how these tools compare.

Something that would be insanely useful is if your tool could be users to do validations.

For example being able to define data types for each column and say required columns. And then run your tool as a validator and take the errors as an array that’d be amazing!

Coming from a dev who’s just over processing CSV files back into my apps.