JSON is valid YAML

YAML is a superset of JSON which means a YAML parser can parse JSON (but not necessarily the other way around).

This test passes:

import io
import json
import yaml

def test_json_is_yaml():
    data = {"name": "Jimmy", "attributes": {"age": 35, "height": 1.89}}
    f = io.StringIO(json.dumps(data))
    from_json = yaml.load(f, Loader=yaml.FullLoader)

    f = io.StringIO(
        """---
name: Jimmy
attributes:
    age: 35
    height: 1.89
"""
    )
    from_yaml = yaml.load(f, Loader=yaml.FullLoader)

    assert from_json == from_yaml

This is noted in the YAML spec:

Both JSON and YAML aim to be human readable data interchange formats. However, JSON and YAML have different priorities. JSON’s foremost design goal is simplicity and universality. Thus, JSON is trivial to generate and parse, at the cost of reduced human readability. It also uses a lowest common denominator information model, ensuring any JSON data can be easily processed by every modern programming environment.

In contrast, YAML’s foremost design goals are human readability and support for serializing arbitrary native data structures. Thus, YAML allows for extremely readable files, but is more complex to generate and parse. In addition, YAML ventures beyond the lowest common denominator data types, requiring more complex processing when crossing between different programming environments.

YAML can therefore be viewed as a natural superset of JSON, offering improved human readability and a more complete information model. This is also the case in practice; every JSON file is also a valid YAML file. This makes it easy to migrate from JSON to YAML if/when the additional features are required.