makevalidator.py

"""
Turn an example dictionary into a voluptious schema
"""
import pprint
import re
import sys

import voluptuous


test_dict =  {
    'exclude': ['Users', 'Uptime'],
    'include': [],
    'set': {
        'snmp_community': 'public',
        'snmp_timeout': 15,
        'snmp_version': '2c',
    },
    'targets': {
        'localhost': {
            'exclude': ['Uptime'],
            'features': {
                'Uptime': {
                    'retries': 3,
                },
                'Users': {
                    'snmp_community': 'monkey',
                    'snmp_port': 15,
                },
            },
            'include': ['Users'],
            'set': {
                'snmp_community': 'monkeys',
                'myset': {1,2,3,4},
                'mytuple': (1,2,3,4)
            },
        },
    },
}


def create_dict_schema(struct):
    """

    Arguments:
    - `struct`: dictionary
    """
    assert isinstance(struct, (dict, list, tuple))

    schema = {}
    for key, val in struct.iteritems():
        if isinstance(val, dict):
            sch = create_dict_schema(val)  # will blow stack for deep trees
            schema[key] = sch
        elif isinstance(val, (list, tuple)) and val:
            if isinstance(val[0], dict):
                sch = create_dict_schema(val[0])
                schema[key] = type(val)([sch])
            else:
                schema[key] = type(val)([type(val[0])])
        else:
            schema[key] = type(val)

    return schema


def doc_to_string(doc):
    schema = create_dict_schema(doc)
    outstr = pprint.pformat(schema)
    return re.sub("<type '(\w+)'>", '\g<1>', outstr)

if __name__ == '__main__':
    if len(sys.argv) == 1:
        schema = create_dict_schema(test_dict)
        outstr = pprint.pformat(schema)
        vschema = voluptuous.Schema(schema)
        assert vschema(test_dict) == test_dict
        print re.sub("<type '(\w+)'>", '\g<1>', outstr)