如何使用 jq 将 object 键转换为数组

Question

我正在尝试转换一个 csv，其中 headers 是键，列中的值是一个列表。

例如我有以下 csv

               mpg   cyl  disp  hp   drat  wt     qsec   vs  am  gear  carb
Mazda RX4      21    6    160   110  3.9   2.62   16.46  0   1   4     4
Mazda RX4 Wag  21    6    160   110  3.9   2.875  17.02  0   1   4     4
Datsun 710     22.8  4    108   93   3.85  2.32   18.61  1   1   4     1

我想要以下格式。

{
    "field1" : [Mazda RX4 ,Mazda RX4 Wag,Datsun 710],    
    "mpg" : [21,21,22.8],    
    "cyl" : [6,6,6],        
    "disp" : [160,160,108],    
   ...
}

请注意，未引用数值。我假设所有列都具有相同的类型。

我正在使用以下 jq 命令。

 curl https://raw.githubusercontent.com/vincentarelbundock/Rdatasets/master/csv/datasets/mtcars.csv  cars.csv | head -n4 | csvtojson | jq '.'

[
  {
    "field1": "Mazda RX4",
    "mpg": "21",
    "cyl": "6",
    "disp": "160",
    "hp": "110",
    "drat": "3.9",
    "wt": "2.62",
    "qsec": "16.46",
    "vs": "0",
    "am": "1",
    "gear": "4",
    "carb": "4"
  },
  {
    "field1": "Mazda RX4 Wag",
    "mpg": "21",
    "cyl": "6",
    "disp": "160",
    "hp": "110",
    "drat": "3.9",
    "wt": "2.875",
    "qsec": "17.02",
    "vs": "0",
    "am": "1",
    "gear": "4",
    "carb": "4"
  },
  {
    "field1": "Datsun 710",
    "mpg": "22.8",
    "cyl": "4",
    "disp": "108",
    "hp": "93",
    "drat": "3.85",
    "wt": "2.32",
    "qsec": "18.61",
    "vs": "1",
    "am": "1",
    "gear": "4",
    "carb": "1"
  }
]

完整的工作解决方案

cat <csv_data> | csvtojson | jq '. as $in | reduce (.[0] | keys_unsorted[]) as $k ( {}; .[$k] = ($in|map(.[$k])))'

jq play - 将所有数字转换为字符串

https://jqplay.org/s/HKjHLVp9KZ

Answer 1

这是一个基于 map 和 reduce 的简洁、高效且概念简单的解决方案：

. as $in
| reduce (.[0] | keys_unsorted[]) as $k ( {}; .[$k] = ($in|map(.[$k])))

将所有数值字符串转换为数字

. as $in
| reduce (.[0] | keys_unsorted[]) as $k ( {}; 
    .[$k] = ($in|map(.[$k] | (tonumber? // .))))

如何使用 jq 将 object 键转换为数组

How to convert object keys to arrays with jq

csv

json

jq

csvtojson

完整的工作解决方案

jq play - 将所有数字转换为字符串

将所有数值字符串转换为数字