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Working with CSV, TSV
Encode/Decode/Roundtrip CSV and TSV files.

Encode

Currently supports arrays of homogenous flat objects, that is: no nesting and it assumes the first object has all the keys required:
- name: Bobo
type: dog
- name: Fifi
type: cat
As well as arrays of arrays of scalars (strings/numbers/booleans):
- [Bobo, dog]
- [Fifi, cat]

Decode

Decode assumes the first CSV/TSV row is the header row, and all rows beneath are the entries. The data will be coded into an array of objects, using the header rows as keys.
name,type
Bobo,dog
Fifi,cat
Note that versions prior to 4.18 require the 'eval/e' command to be specified.
yq e <exp> <file>

Encode CSV simple

Given a sample.yml file of:
- [i, like, csv]
- [because, excel, is, cool]
then
yq -o=csv sample.yml
will output
i,like,csv
because,excel,is,cool

Encode TSV simple

Given a sample.yml file of:
- [i, like, csv]
- [because, excel, is, cool]
then
yq -o=tsv sample.yml
will output
i like csv
because excel is cool

Encode array of objects to csv

Given a sample.yml file of:
- name: Gary
numberOfCats: 1
likesApples: true
height: 168.8
- name: Samantha's Rabbit
numberOfCats: 2
likesApples: false
height: -188.8
then
yq -o=csv sample.yml
will output
name,numberOfCats,likesApples,height
Gary,1,true,168.8
Samantha's Rabbit,2,false,-188.8

Encode array of objects to custom csv format

Add the header row manually, then the we convert each object into an array of values - resulting in an array of arrays. Pick the columns and call the header whatever you like.
Given a sample.yml file of:
- name: Gary
numberOfCats: 1
likesApples: true
height: 168.8
- name: Samantha's Rabbit
numberOfCats: 2
likesApples: false
height: -188.8
then
yq -o=csv '[["Name", "Number of Cats"]] + [.[] | [.name, .numberOfCats ]]' sample.yml
will output
Name,Number of Cats
Gary,1
Samantha's Rabbit,2

Encode array of objects to csv - missing fields behaviour

First entry is used to determine the headers, and it is missing 'likesApples', so it is not included in the csv. Second entry does not have 'numberOfCats' so that is blank
Given a sample.yml file of:
- name: Gary
numberOfCats: 1
height: 168.8
- name: Samantha's Rabbit
height: -188.8
likesApples: false
then
yq -o=csv sample.yml
will output
name,numberOfCats,height
Gary,1,168.8
Samantha's Rabbit,,-188.8

Parse CSV into an array of objects

First row is assumed to be the header row.
Given a sample.csv file of:
name,numberOfCats,likesApples,height
Gary,1,true,168.8
Samantha's Rabbit,2,false,-188.8
then
yq -p=csv sample.csv
will output
- name: Gary
numberOfCats: 1
likesApples: true
height: 168.8
- name: Samantha's Rabbit
numberOfCats: 2
likesApples: false
height: -188.8

Parse TSV into an array of objects

First row is assumed to be the header row.
Given a sample.tsv file of:
name numberOfCats likesApples height
Gary 1 true 168.8
Samantha's Rabbit 2 false -188.8
then
yq -p=tsv sample.tsv
will output
- name: Gary
numberOfCats: 1
likesApples: true
height: 168.8
- name: Samantha's Rabbit
numberOfCats: 2
likesApples: false
height: -188.8

Round trip

Given a sample.csv file of:
name,numberOfCats,likesApples,height
Gary,1,true,168.8
Samantha's Rabbit,2,false,-188.8
then
yq -p=csv -o=csv '(.[] | select(.name == "Gary") | .numberOfCats) = 3' sample.csv
will output
name,numberOfCats,likesApples,height
Gary,3,true,168.8
Samantha's Rabbit,2,false,-188.8
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On this page
Encode
Decode
Encode CSV simple
Encode TSV simple
Encode array of objects to csv
Encode array of objects to custom csv format
Encode array of objects to csv - missing fields behaviour
Parse CSV into an array of objects
Parse TSV into an array of objects
Round trip