# Path

The `path` operator can be used to get the traversal paths of matching nodes in an expression. The path is returned as an array, which if traversed in order will lead to the matching node.

You can get the key/index of matching nodes by using the `path` operator to return the path array then piping that through `.[-1]` to get the last element of that array, the key.

Use `setpath` to set a value to the path array returned by `path`, and similarly `delpaths` for an array of path arrays.

## Map path

Given a sample.yml file of:

```yaml
a:
  b: cat
```

then

```bash
yq '.a.b | path' sample.yml
```

will output

```yaml
- a
- b
```

## Get map key

Given a sample.yml file of:

```yaml
a:
  b: cat
```

then

```bash
yq '.a.b | path | .[-1]' sample.yml
```

will output

```yaml
b
```

## Array path

Given a sample.yml file of:

```yaml
a:
  - cat
  - dog
```

then

```bash
yq '.a.[] | select(. == "dog") | path' sample.yml
```

will output

```yaml
- a
- 1
```

## Get array index

Given a sample.yml file of:

```yaml
a:
  - cat
  - dog
```

then

```bash
yq '.a.[] | select(. == "dog") | path | .[-1]' sample.yml
```

will output

```yaml
1
```

## Print path and value

Given a sample.yml file of:

```yaml
a:
  - cat
  - dog
  - frog
```

then

```bash
yq '.a[] | select(. == "*og") | [{"path":path, "value":.}]' sample.yml
```

will output

```yaml
- path:
    - a
    - 1
  value: dog
- path:
    - a
    - 2
  value: frog
```

## Set path

Given a sample.yml file of:

```yaml
a:
  b: cat
```

then

```bash
yq 'setpath(["a", "b"]; "things")' sample.yml
```

will output

```yaml
a:
  b: things
```

## Set on empty document

Running

```bash
yq --null-input 'setpath(["a", "b"]; "things")'
```

will output

```yaml
a:
  b: things
```

## Set path to prune deep paths

Like pick but recursive. This uses `ireduce` to deeply set the selected paths into an empty object.

Given a sample.yml file of:

```yaml

parentA: bob
parentB:
  child1: i am child1
  child2: i am child2
parentC:
  child1: me child1
  child2: me child2
```

then

```bash
yq '(.parentB.child2, .parentC.child1) as $i
  ireduce({}; setpath($i | path; $i))' sample.yml
```

will output

```yaml
parentB:
  child2: i am child2
parentC:
  child1: me child1
```

## Set array path

Given a sample.yml file of:

```yaml
a:
  - cat
  - frog
```

then

```bash
yq 'setpath(["a", 0]; "things")' sample.yml
```

will output

```yaml
a:
  - things
  - frog
```

## Set array path empty

Running

```bash
yq --null-input 'setpath(["a", 0]; "things")'
```

will output

```yaml
a:
  - things
```

## Delete path

Notice delpaths takes an *array* of paths.

Given a sample.yml file of:

```yaml
a:
  b: cat
  c: dog
  d: frog
```

then

```bash
yq 'delpaths([["a", "c"], ["a", "d"]])' sample.yml
```

will output

```yaml
a:
  b: cat
```

## Delete array path

Given a sample.yml file of:

```yaml
a:
  - cat
  - frog
```

then

```bash
yq 'delpaths([["a", 0]])' sample.yml
```

will output

```yaml
a:
  - frog
```

## Delete - wrong parameter

delpaths does not work with a single path array

Given a sample.yml file of:

```yaml
a:
  - cat
  - frog
```

then

```bash
yq 'delpaths(["a", 0])' sample.yml
```

will output

```bash
Error: DELPATHS: expected entry [0] to be a sequence, but its a !!str. Note that delpaths takes an array of path arrays, e.g. [["a", "b"]]
```