https://stackoverflow.com/questions/24300508/csv-to-json-using-bash

gistfile1.txt

$ xidel -s "so_24300508.csv" -e '$raw'
Africa,Kenya,NAI,109
Africa,Kenya,NAA,160
Asia,India,NSI,100
Asia,India,BSE,60
Asia,Pakistan,ISE,120
Asia,Pakistan,ANO,433
European Union,United Kingdom,LSE,550
European Union,United Kingdom,PLU,123

$ xidel -s "so_24300508.csv" -e 'x:lines($raw) ! array{tokenize(.,",")}'
["Africa", "Kenya", "NAI", "109"]
["Africa", "Kenya", "NAA", "160"]
["Asia", "India", "NSI", "100"]
["Asia", "India", "BSE", "60"]
["Asia", "Pakistan", "ISE", "120"]
["Asia", "Pakistan", "ANO", "433"]
["European Union", "United Kingdom", "LSE", "550"]
["European Union", "United Kingdom", "PLU", "123"]

$ xidel -s "so_24300508.csv" -e 'let $csv:=x:lines($raw) ! array{tokenize(.,",")} return distinct-values($csv(1))'
Africa
Asia
European Union

$ xidel -s "so_24300508.csv" -e '
  array{
    let $csv:=x:lines($raw) ! array{tokenize(.,",")}
    for $region in distinct-values($csv(1))
    return {
      "name":$region,
      "children":array{$csv[.() = $region] ! array:tail(.)}
    }
  }
'
[
  {
    "name": "Africa",
    "children": [
      ["Kenya", "NAI", "109"],
      ["Kenya", "NAA", "160"]
    ]
  },
  {
    "name": "Asia",
    "children": [
      ["India", "NSI", "100"],
      ["India", "BSE", "60"],
      ["Pakistan", "ISE", "120"],
      ["Pakistan", "ANO", "433"]
    ]
  },
  {
    "name": "European Union",
    "children": [
      ["United Kingdom", "LSE", "550"],
      ["United Kingdom", "PLU", "123"]
    ]
  }
]

$ xidel -s "so_24300508.csv" -e '
  let $csv:=x:lines($raw) ! array{tokenize(.,",")}
  for $region in distinct-values($csv(1))
  return
  distinct-values($csv[.() = $region](2))
'
Kenya
India
Pakistan
United Kingdom

$ xidel -s "so_24300508.csv" -e '
  array{
    let $csv:=x:lines($raw) ! array{tokenize(.,",")}
    for $region in distinct-values($csv(1))
    return {
      "name":$region,
      "children":array{
        for $country in distinct-values($csv[.() = $region](2))
        return {
          "name":$country,
          "children":array{$csv[.() = ($country)] ! array:subarray(.,3)}
        }
      }
    }
  }
'
[
  {
    "name": "Africa",
    "children": [
      {
        "name": "Kenya",
        "children": [
          ["NAI", "109"],
          ["NAA", "160"]
        ]
      }
    ]
  },
  {
    "name": "Asia",
    "children": [
      {
        "name": "India",
        "children": [
          ["NSI", "100"],
          ["BSE", "60"]
        ]
      },
      {
        "name": "Pakistan",
        "children": [
          ["ISE", "120"],
          ["ANO", "433"]
        ]
      }
    ]
  },
  {
    "name": "European Union",
    "children": [
      {
        "name": "United Kingdom",
        "children": [
          ["LSE", "550"],
          ["PLU", "123"]
        ]
      }
    ]
  }
]

$ xidel -s "so_24300508.csv" -e '
  array{
    let $csv:=x:lines($raw) ! array{tokenize(.,",")}
    for $region in distinct-values($csv(1))
    return {
      "name":$region,
      "children":array{
        for $country in distinct-values($csv[.() = $region](2))
        return {
          "name":$country,
          "children":array{
            $csv[.() = ($country)] ! {
              "name":.(3),
              "size":.(4)
            }
          }
        }
      }
    }
  }
'
[
  {
    "name": "Africa",
    "children": [
      {
        "name": "Kenya",
        "children": [
          {
            "name": "NAI",
            "size": "109"
          },
          {
            "name": "NAA",
            "size": "160"
          }
        ]
      }
    ]
  },
  {
    "name": "Asia",
    "children": [
      {
        "name": "India",
        "children": [
          {
            "name": "NSI",
            "size": "100"
          },
          {
            "name": "BSE",
            "size": "60"
          }
        ]
      },
      {
        "name": "Pakistan",
        "children": [
          {
            "name": "ISE",
            "size": "120"
          },
          {
            "name": "ANO",
            "size": "433"
          }
        ]
      }
    ]
  },
  {
    "name": "European Union",
    "children": [
      {
        "name": "United Kingdom",
        "children": [
          {
            "name": "LSE",
            "size": "550"
          },
          {
            "name": "PLU",
            "size": "123"
          }
        ]
      }
    ]
  }
]