Preserve order of keys in JSON lists

[rubenvereecken]

Is your feature request related to a problem? Please describe.
I deal with JSON lists of objects, which I convert to CSV. The key order between the objects is consistent, yet in the output is random.

Describe the solution you'd like
We already have preserved key order for regular objects:

$ echo '{"z":1,"a":2,"c":3}' | dasel -r json -w csv
z,a,c
1,2,3

I would love to have the same feature for lists of objects – ie:

$ echo '[{"z":1,"a":2,"c":3},{"z":1,"a":2,"c":3}]' | dasel -r json -w csv                                                                                                                                                     
z,a,c
1,2,3
1,2,3

Instead, what currently happens is:

$ echo '[{"z":1,"a":2,"c":3},{"z":1,"a":2,"c":3}]' | dasel -r json -w csv                                                                                                                                                     
a,c,z
2,3,1
2,3,1

[TomWright]

This is only an issue when writing to CSV:

$ echo '[{"z":1,"a":2,"c":3},{"z":1,"a":2,"c":3}]' | dasel -r json
[
  {
    "z": 1,
    "a": 2,
    "c": 3
  },
  {
    "z": 1,
    "a": 2,
    "c": 3
  }
]
$ echo '[{"z":1,"a":2,"c":3},{"z":1,"a":2,"c":3}]' | dasel -r json -w yaml
- z: 1
  a: 2
  c: 3
- z: 1
  a: 2
  c: 3

More of a note to myself at the moment - hopefully I can better integrate the CSV parser in use.

[datatraveller1]

dasel is a great tool, thank you very much!
I have encountered the same issue when using dasel -r json -w csv
The field order in the CSV is by alphabetically sorted json keys instead of keeping the original JSON key order.
It would be great if this could be fixed soon.

[datatraveller1]

Hi @TomWright Is there a workaround to keep the original JSON key order?
I have experimented with
dasel -f test.json -r json -w csv "all().mapOf(z,z,a,a,c,c).merge()"
but this doesn't keep the field order either.

test.json:

[
  {
    "z": 1,
    "a": 2,
    "c": 3
  },
  {
    "z": 1,
    "a": 2,
    "c": 3
  }
]

Result:

a,c,z
2,3,1
2,3,1

[TomWright]

@datatraveller1 sorry but no there isn't. The issue is in the CSV writer itself.

[TomWright]

@datatraveller1 just to note I'm not ignoring this issue. It is resolved in V3 which I plan on releasing soon

[datatraveller1]

Great thank you very much.