yq/pkg/yqlib/doc/operators/pick.md
2022-03-10 13:50:53 +11:00

54 lines
960 B
Markdown

# Pick
Filter a map by the specified list of keys. Map is returned with the key in the order of the pick list.
Similarly, filter an array by the specified list of indices.
{% hint style="warning" %}
Note that versions prior to 4.18 require the 'eval/e' command to be specified. 
`yq e <exp> <file>`
{% endhint %}
## Pick keys from map
Note that the order of the keys matches the pick order and non existent keys are skipped.
Given a sample.yml file of:
```yaml
myMap:
cat: meow
dog: bark
thing: hamster
hamster: squeek
```
then
```bash
yq '.myMap |= pick(["hamster", "cat", "goat"])' sample.yml
```
will output
```yaml
myMap:
hamster: squeek
cat: meow
```
## Pick indices from array
Note that the order of the indexes matches the pick order and non existent indexes are skipped.
Given a sample.yml file of:
```yaml
- cat
- leopard
- lion
```
then
```bash
yq 'pick([2, 0, 734, -5])' sample.yml
```
will output
```yaml
- lion
- cat
```