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
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

Last modified 4mo ago