# bone_hierarchy()

Returns the parent and child relationship of the bones. It is the same map as the Hierarchy view in the Quick Skin window.

Use it when a script walks an arm chain. The weight numbers themselves are not in it.

### Signature
```python
skin.bone_hierarchy() -> dict
```

### Example
```python
tree = api.skin().bone_hierarchy()
print(tree.get("Bip001 Spine"))
```