Skip to main content

declarative de/serialization of python structures

Project description

As a result of frustration working with colander, I decided to create something similar…

Objective is a de/serialization tool with following features:

  • declarative definition of objectives.
  • no confusion about how to define something, it is always the same.
  • reuse definitions by inheritance.
  • optional validation.
  • make it simple to override certain parts.

Usage

Simple mapping and validation

import objective
import datetime


now = datetime.datetime(2001, 9, 11)


class UserObjective(objective.Mapping):

    name = objective.Item(objective.Unicode, missing=objective.Ignore)
    email = objective.Item(objective.Unicode, validator=objective.Email())
    password = objective.Item(objective.Unicode)
    since = objective.Item(objective.UtcDateTime, missing=now)


serialized = {
    'email': 'foo@example.com',
    'password': 'foobar'
}


deserialized = UserObjective.deserialize(serialized)


assert deserialized == {
    'password': u'foobar',
    'email': u'foo@example.com',
    'since': datetime.datetime(2001, 9, 11, 0, 0)
}


bad_serialized = {
    'name': 'foobar'
}


try:
    deserialized = UserObjective().deserialize(bad_serialized)

except objective.Invalid as e:

    assert isinstance(e, objective.exc.InvalidChildren)
    assert {(x.node.__name__, x.__class__, x.value) for x in e.children} == {
        ('password', objective.exc.MissingValue, objective.values.Undefined),
        ('email', objective.exc.InvalidValue, 'baz')
    }

Mapping complex structures

import objective


class ProductRequestObjective(objective.BunchMapping):
    @objective.Item()
    class body(objective.Mapping):
        name = objective.Item(objective.Unicode)
        root = objective.Item(objective.Unicode)

        @objective.Item()
        class semantics(objective.List):
            items = objective.Item(objective.Unicode)

    @objective.Item()
    class match(objective.Mapping):
        _id = objective.Item(objective.Field)

Issues, thoughts, ideas

objective is far from complete. There are tons of possible validators I can imagine.

I tried my best (mostly in terms of time) to test.

If you find bugs or you have a great idea, I am totally open to implement it.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Files for objective, version 0.0.13
Filename, size File type Python version Upload date Hashes
Filename, size objective-0.0.13-py2.py3-none-any.whl (10.2 kB) File type Wheel Python version py2.py3 Upload date Hashes View

Supported by

Pingdom Pingdom Monitoring Google Google Object Storage and Download Analytics Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN DigiCert DigiCert EV certificate StatusPage StatusPage Status page