Validators

This module implements JSON Schema draft03 and draft04.

Basic

from jsonspec.validators import load

# data will validate against this schema
validator = load({
    'title': 'Example Schema',
    'type': 'object',
    'properties': {
        'age': {
            'description': 'Age in years',
            'minimum': 0,
            'type': 'integer'
        },
        'firstName': {
            'type': 'string'
        },
        'lastName': {
            'type': 'string'
        }
    },
    'required': [
        'firstName',
        'lastName'
    ]
})

# validate this data
validator.validate({
    'firstName': 'John',
    'lastName': 'Noone',
    'age': 33,
})

Choose specification

Schemas will be parsed by the draft04 specification by default. You can setup, or even better mix between draft03 and draft04.

Show these examples:

validator = load({
    'id': 'foo',
    'properties': {
        'bar': {
            'id': 'baz'
        },
    },
})
foo schema:parsed with draft04
baz schema:parsed with draft04 
validator = load({
    'id': 'foo',
    'properties': {
        'bar': {
            'id': 'baz'
        },
    },
}, spec='http://json-schema.org/draft-03/schema#')
foo schema:parsed with draft03
baz schema:parsed with draft03 
validator = load({
    'id': 'foo',
    'properties': {
        'bar': {
            '$schema': 'http://json-schema.org/draft-03/schema#',
            'id': 'baz'
        },
    },
})
foo schema:parsed with draft04
baz schema:parsed with draft03

About format

This module implements a lot of formats, exposed to every draft:

name description enabling
email validate email  
hostname validate hostname  
ipv4 validate ipv4 pip install json-spec[ip]
ipv6 validate ipv6 pip install json-spec[ip]
regex validate regex  
uri validate uri  
css.color validate css color  
rfc3339.datetime see rfc3339  
utc.datetime YYYY-MM-ddThh:mm:SSZ  
utc.date YYYY-MM-dd  
utc.time hh:mm:SS  
utc.millisec any integer, float  

Some formats rely on external modules, and they are not enabled by default.

Each draft validator aliases they formats to these formats. See draft04 and draft03 methods for more details.

Regarding your needs, you can register your own formats. Use entry_points in your setup.py. for example:

[entry_points]

jsonspec.validators.formats =
    my:format = my.module:validate_format

API

validators.load(schema, uri=None, spec=None, provider=None)

Scaffold a validator against a schema.

Parameters:
  • schema (Mapping) – the schema to compile into a Validator
  • uri (Pointer, str) – the uri of the schema. it may be ignored in case of not cross referencing.
  • spec (str) – fallback to this spec if the schema does not provides ts own
  • provider (Mapping, Provider...) – the other schemas, in case of cross referencing
validators.draft04.compile(schema, pointer, context, scope=None)

Compiles schema with JSON Schema draft-04.

Parameters:
  • schema (Mapping) – obj to compile
  • pointer (Pointer, str) – uri of the schema
  • context (Context) – context of this schema
validators.register(compiler=None, spec=None)

Expose compiler to factory.

Parameters:
  • compiler (callable) – the callable to expose
  • spec (str) – name of the spec

It can be used as a decorator:

@register(spec='my:first:spec')
def my_compiler(schema, pointer, context):
    return Validator(schema)

or as a function:

def my_compiler(schema, pointer, context):
    return Validator(schema)

register(my_compiler, 'my:second:spec')
class validators.ReferenceValidator(pointer, context)

Reference a validator to his pointer.

Variables:
  • pointer – the pointer to the validator
  • context – the context object
  • default – return the default validator
  • validator – return the lazy loaded validator
 
>>> validator = ReferenceValidator('http://json-schema.org/geo#', context)
>>> assert validator({
>>>     'latitude': 0.0124,
>>>     'longitude': 1.2345
>>> })
validate(obj, pointer=None)

Validate object against validator.

Parameters:
  • obj – the object to validate
  • pointer – the object pointer
class validators.Draft03Validator(attrs, uri=None, formats=None)

Implements JSON Schema draft-03 validation.

Variables:
  • attrs – attributes to validate against
  • uri – uri of the current validator
  • formats – mapping of available formats
 
>>> validator = Draft03Validator({'min_length': 4})
>>> assert validator('this is sparta')
fail(reason, obj, pointer=None)

Called when validation fails.

has_default()

docstring for has_default

is_optional()

True by default.

validate(obj, pointer=None)

Validate object against validator

Parameters:obj – the object to validate
validate_format(obj, pointer=None)
Expected draft03 Alias of
color css.color
date-time utc.datetime
date utc.date
time utc.time
utc-millisec utc.millisec
regex regex
style css.style
phone phone
uri uri
email email
ip-address ipv4
ipv6 ipv6
host-name hostname
class validators.Draft04Validator(attrs, uri=None, formats=None)

Implements JSON Schema draft-04 validation.

Variables:
  • attrs – attributes to validate against
  • uri – uri of the current validator
  • formats – mapping of available formats
 
>>> validator = Draft04Validator({'min_length': 4})
>>> assert validator('this is sparta')
fail(reason, obj, pointer=None)

Called when validation fails.

is_optional()

Returns True, beceause it is meaningless in draft04.

validate(obj, pointer=None)

Validate object against validator

Parameters:obj – the object to validate
validate_format(obj, pointer=None)
Expected draft04 Alias of
date-time rfc3339.datetime
email email
hostname hostname
ipv4 ipv4
ipv6 ipv6
uri uri
class validators.Context(factory, registry, spec=None, formats=None)
Variables:
  • factory – global factory
  • registry – the current registry
  • spec – the current spec
  • formats – the current formats exposed
class validators.Factory(provider=None, spec=None, formats=None)
Variables:
  • provider – global registry
  • spec – default spec

Exceptions

class validators.CompilationError(message, schema)

Raised while schema parsing

class validators.ReferenceError(*args)

Raised while reference error

class validators.ValidationError(reason, obj=None, pointer=None, errors=None)

Raised when validation fails

flatten()

Flatten nested errors.

{pointer: reasons}