Validating a yaml document in python

Question

One of the benefits of XML is being able to validate a document against an XSD. YAML doesn\'t have this feature, so how can I validate that the YAML document I open is in th

Answer 1

You can load YAML document as a dict and use library schema to check it:

from schema import Schema, And, Use, Optional, SchemaError
import yaml

schema = Schema(
        {
            'created': And(datetime.datetime),
            'author': And(str),
            'email': And(str),
            'description': And(str),
            Optional('tags'): And(str, lambda s: len(s) >= 0),
            'setup': And(list),
            'steps': And(list, lambda steps: all('=>' in s for s in steps), error='Steps should be array of string '
                                                                                  'and contain "=>" to separate'
                                                                                  'actions and expectations'),
            'teardown': And(list)
        }
    )

with open(filepath) as f:
   data = yaml.load(f)
   try:
       schema.validate(data)
   except SchemaError as e:
       print(e)