Use jq to remove key/value pairs based on other file - json

I have 2 json files containing translations for my app:
en-US.json:
{
"car": "car",
"bike": "bike",
"tree": "tree",
}
nl-NL.json:
{
"car": "auto",
"bike": "fiets",
"tree": "boom",
"house": "huis"
}
As you can see, I have removed the house from the en-US.json file (among many others). How could I remove the same house entry from my nl-NL.json file with jq? I basically want to get the intersection of both files, based on key.
I've been playing with jq 'keys' to get all keys, but that does not work. I think it should be found in the direction of jq --slurpfile en en-US.json 'del($en)' nl-NL.json but that totally does not work :( Any suggestions?

To reduce the nl-NL.json file to the keys present in en-US.json, you could read in the latter as reference, then select from the input turned into entries those keys that are present in the reference file. in checks "whether or not the input key is in the given object".
jq --argfile ref en-US.json 'with_entries(select(.key | in($ref)))' nl-NL.json
{
"car": "auto",
"bike": "fiets",
"tree": "boom"
}

You're looking for something like this:
$ jq 'del(.[(keys - (input | keys))[]])' nl-NL.json en-US.json
{
"car": "auto",
"bike": "fiets",
"tree": "boom"
}

Related

Merging multiple JSON Lines files into a single JSON object

I'm trying to merge / reduce many JSON objects and somehow I'm not getting the expected result.
I'm only interested in getting all keys, the values and the number of items inside arrays are irrelevant.
file1.json:
{
"customerId": "xx",
"emails": [
{
"address": "james#zz.com",
"customType": "",
"type": "custom"
},
{
"address": "sales#x.com",
"primary": true
},
{
"address": "info#x.com"
}
]
}
{
"id": "654",
"emails": [
{
"address": "peter#x.com",
"primary": true
}
]
}
The desired output is a JSON object with all possible keys from all input objects. The values are irrelevant, any value from any input object is OK. But all keys from input objects must be present in output object:
{
"emails": [
{
"address": "james#zz.com", <--- any existing value works
"customType": "", <--- any existing value works
"type": "custom", <--- any existing value works
"primary": true <--- any existing value works
}
],
"customerId": "xx", <--- any existing value works
"id": "654" <--- any existing value works
}
I tried reducing it, but it misses many of the keys in the array:
$ jq -s 'reduce .[] as $item ({}; . + $item)' file1.json
{
"customerId": "xx",
"emails": [
{
"address": "peter#x.com",
"primary": true
}
],
"id": "654"
}
The structure of the objects contained in file1.json is unknown, so the solution must be agnostic of any keys/values and the solution must not assume any structure or depth.
Is it possible to fix this somehow considering how jq works? Or is it possible to solve this issue using another tool?
PS: For those of you that are curious, this is useful to infer a schema that can be created in a database. Given an arbitrary number of JSON objects with an arbitrary structure, it's easy to create a single JSON squished/merged/fused structure that will "accommodate" all JSON objects.
BigQuery is able to autodetect a schema, but only 500 lines are analyzed to come up with it. This presents problems if objects have different structures past that 500 line mark.
With this approach I can squish a JSON Lines file with 1000000s of objects into one line that can be then imported into BigQuery with the autodetect schema flag and it will work every time since BigQuery only has one line to analyze and this line is the "super-schema" of all the objects. After extracting the autodetected schema I can manually fine tune it to make sure types are correct and then recreate the table specifying my tuned schema:
$ ls -1 users*.json | wc --lines
3672
$ cat users*.json > users-all.json
$ cat users-all.json | wc --lines
146482633
$ jq 'squish' users-all.json > users-all-squished.json
$ cat users-all-squished.json | wc --lines
1
$ bq load --autodetect users users-all-squished.json
$ bq show schema --format=prettyjson users > users-schema.json
$ vi users-schema.json
$ bq rm --table users
$ bq mk --table users --schema=users-schema.json
$ bq load users users-all.json
[Some options are missing or changed for readability]
Here is a solution that produces the expected result in the sample example, and seems to meet all the stated requirements. It is similar to one proposed by #pmf on this page.
jq -n --stream '
def squish: map(if type == "number" then 0 else . end);
reduce (inputs | select(length==2)) as [$p, $v] ({}; setpath($p|squish; $v))
'
Output
For the example given in the Q, the output is:
{
"customerId": "xx",
"emails": [
{
"address": "peter#x.com",
"customType": "",
"type": "custom",
"primary": true
}
],
"id": "654"
}
As #peak has pointed out, some aspects are underspecified. For instance, what should happen with .customerId and .id? Are they always the same across all files (as suggested by the sample files provided)? Do you want the items of the .emails array just thrown into one large array, or do you want to have them "merged" by some criteria (e.g. by a common value in their .address field)? Here are some stubs to start from:
Simply concatenate the .emails arrays and take all other parts from the first file:
jq 'reduce inputs as $in (.; .emails += $in.emails)' file*.json
# or simpler
jq '.emails += [inputs.emails[]]' file*.json
Demo Demo
{
"emails": [
{
"address": "cc#xx.com"
},
{
"address": "james#zz.com",
"customType": "",
"type": "custom"
},
{
"address": "james#x.com"
},
{
"address": "sales#x.com",
"primary": true
},
{
"address": "info#x.com"
},
{
"address": "james#x.com"
},
{
"address": "sales#x.com",
"primary": true
},
{
"address": "info#x.com"
}
],
"customerId": "xx",
"id": "654"
}
Merge the objects in the .emails array by a common value in their .address field, with latter values overwriting former values for other fields with colliding names, and discard all other parts from the files:
jq -n 'reduce inputs.emails[] as $e ({}; .[$e.address] += $e) | map(.)' file*.json
Demo
[
{
"address": "cc#xx.com"
},
{
"address": "james#zz.com",
"customType": "",
"type": "custom"
},
{
"address": "james#x.com"
},
{
"address": "sales#x.com",
"primary": true
},
{
"address": "info#x.com"
}
]
If you are only interested in a list of unique field names for a given address, regardless of the counts and values used, you can also go with:
jq -n '
reduce inputs.emails[] as $e ({}; .[$e.address][$e | keys_unsorted[]] = 1)
| map_values(keys)
'
Demo
{
"cc#xx.com": [
"address"
],
"james#zz.com": [
"address",
"customType",
"type"
],
"james#x.com": [
"address"
],
"sales#x.com": [
"address",
"primary"
],
"info#x.com": [
"address"
]
}
The structure of the objects contained in file1.json is unknown, so the solution must be agnostic of any keys/values and the solution must not assume any structure or depth.
You can use the --stream flag to break down the structure into an array of paths and values, discard the values part and make the paths unique:
jq --stream -nc '[inputs[0]] | unique[]' file*.json
["customerId"]
["emails"]
["emails",0,"address"]
["emails",0,"customType"]
["emails",0,"primary"]
["emails",0,"type"]
["emails",1,"address"]
["emails",2]
["emails",2,"address"]
["emails",2,"primary"]
["emails",3]
["emails",3,"address"]
["id"]
Trying to build a representation of this, similar to any of the input files, comes with a lot of caveats. For instance, how would you represent in a single structure if one file had .emails as an array of objects, and another had .emails as just an atomic value, say, a string. You would not be able to represent this plurality without introducing new, possibly ambiguous structures (e.g. putting all possibilities into an array).
Therefore, having a list of paths could be a fair compromise. Judging by your desired output, you want to focus more on the object structure, so you could further reduce complexity by discarding the array indices. Depending on your use case, you could replace them with a single value to retain the information of the presence of an array, or discard them entirely:
jq --stream -nc '[inputs[0] | map(numbers = 0)] | unique[]' file*.json
["customerId"]
["emails"]
["emails",0]
["emails",0,"address"]
["emails",0,"customType"]
["emails",0,"primary"]
["emails",0,"type"]
["id"]
jq --stream -nc '[inputs[0] | map(strings)] | unique[]' file*.json
["customerId"]
["emails"]
["emails","address"]
["emails","customType"]
["emails","primary"]
["emails","type"]
["id"]
The following program meets these two key requirements:
"all keys from input objects must be present in output object";
"the solution must be agnostic of any keys/values and the solution must not assume any structure or depth."
The approach is the same as one suggested by #pmf, and for the example given in the Q, produces results that are very similar to the one that is shown:
jq -n --stream '
def squish: map(select(type == "string"));
reduce (inputs | select(length==2)) as [$p, $v] ({};
setpath($p|squish; $v))
'
With the given input, this produces:
{
"customerId": "xx",
"emails": {
"address": "peter#x.com",
"customType": "",
"type": "custom",
"primary": true
},
"id": "654"
}

Create object from stream of objects keyed by a property in jq

This is a question about the command line json processor jq. It is not about javascript or jQuery or anything else with js and qs in its name :-)
I have input data like:
{ "id": "person1", "name": "wilma", "age": "quite old"}
{ "id": "person2", "name": "fred"}
{ "id": "person1", "name": "betty", "x": "extra"}
I want output like this:
{
"person1": { "name": "betty", "age": "quite old", "x": "extra" },
"person2": { "name": "fred" }
}
I have tried various things!
e.g.
jq -s '.[] | { (.id) : . }' <data
gives
{ "person1": { "id": "person1", "name": "wilma", "age": "quite old" }}
{ "person2": { "id": "person2", "name": "fred" }}
{ "person1": { "id": "person1", "name": "betty", "x": "extra" }}
Which is sort of there, except it's outputting a stream of objects instead of just one. I need to merge all those objects together.
jqplay.org example
I've also tried using group_by(.id)[]|add which merges each item but still results in a stream. https://jqplay.org/s/lh6QUQ0DO4
You could tweak your attempt as follows:
jq -s 'map({ (.id) : . }) | add' <data
However, it would be more efficient to use inputs and reduce with the -n command-line option instead of -s.
Of course, using this approach runs the risk of collisions.
You might also want to add del(.id)
Ah! I've got it! Or I've got one solution - please post if there's a better way.
jq -s '[group_by(.id)[]| add | { (.id) : . } ]|add' <data
https://jqplay.org/s/BfAdRBZUMW
group_by groups the inputs by their .id value and produces an array of arrays - the inner arrays are the values that match on id.
for each group the inner arrays are passed to add which, because the things in the inner arrays are objects, merges them.
That leaves a 2 item array. We feed that to an object constructor which plucks the id as the key and the whole item as the value. This still leaves an array of items.
the outer [] (starts at start of pattern) says take all those and feed it to add (again), which merges the final objects created in (3).
It works, but there may be a cleaner way.
EDIT
This is uglier but produces the same result and is ~24% faster on a 9MB dataset.
jq -s 'reduce [.[]|{ (.id) : . }][] as $item ({}; . * $item )' <data
This uses reduce <list> as <$var> (<initiation>; <iteration>) starting with an empty object {} and using the merge operator * starting from the incoming item . to create the output. I'm surprised it's faster, but I understand that group_by does a sort, so I guess that's an additional time cost.

Get parent value from json using jq

My json file looks like this;
{
"RQBTYFE86MFC3oL": {
"name": "Nightmode",
"lights": [
"1",
"2",
"3",
"4",
"5",
"7",
"8",
"9",
"10",
"11"
],
"owner": "kvovodUUfn2vlby9h9okdDhv8SrTzkBFjk6kPz2v",
"recycle": false,
"locked": false,
"appdata": {
"version": 1,
"data": "QSXCj_r01_d99"
},
"picture": "",
"lastupdated": "2018-08-08T03:21:39",
"version": 2
}
}
I want to get the 'RQBTYFE86MFC3oL' value by doing a query for 'Nightmode'. So far I came up with this;
jq '.[] | select(.name == "Nightmode")'
This will return me the correct part of the Json but the 'RQBTYFE86MFC3oL' part is stripped. How do I get this part as well?
A simple way to determine the key name(s) corresponding to values satisfying a certain condition is to use to_entries, as explained in the jq manual.
Using this approach, the appropriate jq filter would be:
to_entries[] | select(.value.name == "Nightmode") | .key
with the result:
"RQBTYFE86MFC3oL"
If you want to get the key-value pair, you'd use with_entries as follows:
with_entries( select(.value.name == "Nightmode") )
If the input JSON is too large to fit comfortably in memory, then it would make sense to use jq's streaming parser (invoked with the --stream command-line option):
jq --stream '
select(.[1] == "Nightmode" and (first|length) == 2 and first[1] == "name")
| first | first'
This would produce the key name.
The key idea is that the streaming parser produces arrays including pairs of the form: [ARRAYPATH, VALUE] where VALUE is the value at ARRAYPATH.
You want to get the Key Value.
So use the keys command, to return 'RQBTYFE86MFC3oL' as that is the key, the rest is the value of that key.
jq 'keys'
Here is a snippet: https://jqplay.org/s/YvpCb2PH42
Reference: https://stedolan.github.io/jq/manual/

How to update a subitem in a json file using jq?

Using jq I tried to update this json document:
{
"git_defaults": {
"branch": "master",
"email": "jenkins#host",
"user": "Jenkins"
},
"git_namespaces": [
{
"name": "NamespaceX",
"modules": [
"moduleA",
"moduleB",
"moduleC",
"moduleD"
]
},
{
"name": "NamespaceY",
"modules": [
"moduleE"
]
}
]
}
with adding moduleF to NamespaceY. I need to write the file back again to the original source file.
I came close (but no cigar) with:
jq '. | .git_namespaces[] | select(.name=="namespaceY").modules |= (.+ ["moduleF"])' config.json
and
jq '. | select(.git_namespaces[].name=="namespaceY").modules |= (.+ ["moduleF"])' config.json
The following filter should perform the update you want:
(.git_namespaces[] | select(.name=="NamespaceY").modules) += ["moduleF"]
Note that the initial '.|' in your attempt is not needed; that "NamespaceY" is capitalized in config.json; that the parens as shown are the keys to success; and that += can be used here.
One way to write back to the original file would perhaps be to use 'sponge'; other possibilities are discussed on the jq FAQ https://github.com/stedolan/jq/wiki/FAQ

Using jq to list keys in a JSON object

I have a hierarchically deep JSON object created by a scientific instrument, so the file is somewhat large (1.3MB) and not readily readable by people. I would like to get a list of keys, up to a certain depth, for the JSON object. For example, given an input object like this
{
"acquisition_parameters": {
"laser": {
"wavelength": {
"value": 632,
"units": "nm"
}
},
"date": "02/03/2525",
"camera": {}
},
"software": {
"repo": "github.com/username/repo",
"commit": "a7642f",
"branch": "develop"
},
"data": [{},{},{}]
}
I would like an output like such.
{
"acquisition_parameters": [
"laser",
"date",
"camera"
],
"software": [
"repo",
"commit",
"branch"
]
}
This is mainly for the purpose of being able to enumerate what is in a JSON object. After processing the JSON objects from the instrument begin to diverge: for example, some may have a field like .frame.cross_section.stats.fwhm, while others may have .sample.species, so it would be convenient to be able to interrogate the JSON object on the command line.
The following should do exactly what you want
jq '[(keys - ["data"])[] as $key | { ($key): .[$key] | keys }] | add'
This will give the following output, using the input you described above:
{
"acquisition_parameters": [
"camera",
"date",
"laser"
],
"software": [
"branch",
"commit",
"repo"
]
}
Given your purpose you might have an easier time using the paths builtin to list all the paths in the input and then truncate at the desired depth:
$ echo '{"a":{"b":{"c":{"d":true}}}}' | jq -c '[paths|.[0:2]]|unique'
[["a"],["a","b"]]
Here is another variation uing reduce and setpath which assumes you have a specific set of top-level keys you want to examine:
. as $v
| reduce ("acquisition_parameters", "software") as $k (
{}; setpath([$k]; $v[$k] | keys)
)