b3j0f.schema 0.0.9

Python schema library agnostic from languages.

Description

Python schema library agnostic from languages.

Links

• Homepage

• PyPI

• Documentation

Installation

pip install b3j0f.schema

Features

This library provides an abstraction layer for manipulating schema from several languages.

The abstraction layer is a python object which can validate data (properties to validate are object attributes or dictionary items) and be dumped into a dictionary or specific language format.

Supported languages are:

• python

• json

• xsd

It is also possible to generate a schema from a dictionary. And validation rules are fully and easily customisable thanks to using a schema such as a property.

Example

Data Validation

from b3j0f.schema import build, validate

# json format with required subinteger property
resource = '{"title": "test", "properties": {"subname": {"type": "string", "default": "test"}}, {"subinteger": {"type": "integer"}}, "required": ["subinteger"]}'
Test = build(resource)

test = Test(subname='example')

assert test.subinteger == 0  # instanciation value
assert Test.subinteger.default == 0  # default value
assert test.subname == 'example' # instanciation value
assert Test.subname.default == 'test'  # instanciation value

error = None
try:
   test.subname = 2  # wrong setting because subname is not a string

except TypeError as error:
   pass

assert error is not None

assert 'subname' in Test.getschemas()

validate(Test.subinteger, 1)  # validate property
validate(test, {'subinteger': 1})  # validate dictionary

class Sub(object):  # object to validate with required subinteger
   subinteger = 1

validate(test, Sub)  # validate an object with required subinteger
validate(test, Sub())

wrongvalues = [
   '',  # object without subinteger
   {'subinteger': ''},  # wrong data type for subinteger
   {}  # dictionary without the required property subinteger
]

for wrongvalue in wrongvalues:

   error = None
   try:
      validate(test, wrongvalues)

   except TypeError as error:
      pass

   assert error is not None

Schema retrieving

from b3j0f.schema import register, getbyname, getbyuuid, data2schema

assert getbyuuid(test.uuid) is None
assert test not in getbyname(test.name)

register(test)

assert test is getbyuuid(test.uuid)

assert test in getbyname(test.name)

schema = data2schema(2, name='vint')  # get an integer schema with 2 such as a default value and name vint

assert schema.default == 2
assert schema.name == 'vint'

error = None
try:
   schema.default = ''

except TypeError as error:
   pass

assert error is not None

Schema definition

from b3j0f.schema import Schema, updatecontent

@updatecontent  # change public attributes/functionss to schemas
class Test(Schema):

   subname = 'test'  # specify inner schema such as a string schema with default value 'test'
   subinteger = 1  # speciy inner schema sub as an integer with default value 1

test = Test()

test = Test(subname='example')

assert test.subname == 'example' # instanciation value
assert Test.subname.default == 'test'  # instanciation value
assert test.subinteger == 1  # instanciation value
assert Test.subinteger.default == 1  # default value

error = None
try:
   test.subname = 2  # wrong setting because subname is not a string

except TypeError as error:
   pass

assert error is not None

assert 'subname' in Test.getschemas()

Complex Schema definition

from b3j0f.schema import Schema, ThisSchema, RefSchema, build
from random import random

@build(foo=2)  # transform a python class to a schema class with the additional property foo
class Test(object):

   key = DynamicValue(lambda: random())  # generate a new key at each instanciation
   subtest = ThisSchema(key=3.)  # use this schema such as inner schema
   ref = RefSchema()  # ref is validated by this schema

assert issubclass(Test, Schema)

test1, test2 = Test(), Test()

# check foo
assert test1.foo == test2.foo == 2

# check key and subtest properties
assert test1.key != test2.key
assert test1.subtest.key == test2.subtest.key == 3.

# check ref
assert test1.ref is None
test1.ref = Test()

error = None
try:
   test.ref = 2

except TypeError as error:
   pass

assert error is not None

Function schema definition

from b3j0f.schema import FunctionSchema, ParamSchema, FloatSchema, BooleanSchema, StringSchema, ArraySchema, OneOfSchema

@data2schema
def test(a, b, c=2, d=None, e=None, f=None):  # definition of a shema function. Parameter values and (function) types are defined in the signature and the docstring.
   """
   :param float a: default 0.
   :type b: bool
   :type d: ints  # list of int
   :type e: list of str  #: list of str
   :type f: int,float  #: one of (int, float)
   :rtype: str
   """

   return a, b, c

assert isinstance(test, FunctionSchema)
assert isinstance(test.params, ArraySchema)
assert isinstance(test.params[0], ParamSchema)
assert len(test.params) == 6

assert test.params[0].name == 'a'
assert test.params[0].mandatory == True
assert isinstance(test.params[0].ref, FloatSchema)
assert test.params[0].default is 0.

assert test.params[1].name == 'b'
assert isinstance(test.params[1].ref, BooleanSchema)
assert test.params[1].mandatory is True
assert test.params[1].default is False

assert test.params[2].name == 'c'
assert isinstance(test.params[2].ref, IntegerSchema)
assert test.params[2].mandatory is False
assert test.params[2].default is 2

assert test.params[3].name == 'd'
assert isinstance(test.params[3].ref, ArraySchema)
assert isinstance(test.params[3].ref.itemtype, IntegerSchema)
assert test.params[3].mandatory is False
assert test.params[3].default is None

assert test.params[4].name == 'e'
assert isinstance(test.params[4].ref, ArraySchema)
assert isinstance(test.params[4].ref.itemtype, StringSchema)
assert test.params[4].mandatory is False
assert test.params[4].default is None

assert test.params[5].name == 'f'
assert isinstance(test.params[5].ref, OneOfSchema)
assert isinstance(test.params[5].ref.schemas[0], IntegerSchema)
assert isinstance(test.params[5].ref.schemas[1], FloatSchema)
assert test.params[5].mandatory is False
assert test.params[5].default is None

assert test.rtype is StringSchema

assert test(1, 2) == 'test'

Generate a schema from a data

from b3j0f.schema import data2schema

data = {  # data is a dict
   'a': 1
}

schemacls = dict2schemacls(data, name='test')

assert isinstance(schemacls.a, IntegerSchema)
assert schemacls.a.default is 1
assert isinstance(schemacls.name, StringSchema)
assert schemacls.name.default == 'test'

validate(schemacls(), data)

class Test(object):  # data is an object
   a = 1

schemacls = dict2schemacls(data, name='test')

assert isinstance(schemacls.a, IntegerSchema)
assert schemacls.a.default is 1
assert isinstance(schemacls.name, StringSchema)
assert schemacls.name.default == 'test'

validate(schemacls(), Test)
validate(schemacls(), Test())

Schema property getting/setting/deleting customisation such as a property

class Test(Schema):

   @Schema
   def test(self):
      self.op =  'get'
      return getattr(self, '_test', 1)

   @test.setter
   def test(self, value):
      self.op = 'set'
      self._test = value

   @test.deleter
   def test(self):
      self.op = 'del'
      del self._test

test = Test()

# check getter
assert test.test == 1
assert test.op == 'get'

# check setter
test.test = 2
assert test.op == 'set'
assert test.test == 2

# check deleter
del test.test
assert test.op == 'del'
assert test.test == 1

Perspectives

• wait feedbacks during 6 months before passing it to a stable version.

• Cython implementation.

Donation