pyyaml - using anchors across two YAML documents in the same file

host.yaml

---
host: phl-42
datacenter:
  location: &BLR Bangalore
  cabinet: !!str 13
  unit: 3
roles:
  - webserver
  - wp_database
---
host: phl-43
datacenter: 
  location: *BLR
  cabinet: !!str 13
  unit: 4
roles:
  - webserver
  - wp_database
...
---

yaml_parser.py

import yaml

def my_compose_document(self):
    self.get_event()
    node = self.compose_node(None, None)
    self.get_event()
    return node

yaml.composer.Composer.compose_document = my_compose_document

with open("host.yml", "r") as f:
    docs = yaml.load_all(f, Loader=yaml.FullLoader)

    for doc in docs:
        if doc:
            for k, v in doc.items():
                print(f"{k}: {v}")
        else:
            break
        print()