marshmallow is an ORM/ODM/framework-agnostic library for converting complex datatypes, such as objects, to and from native Python datatypes.

from datetime import date
from marshmallow import Schema, fields, pprint

class ArtistSchema(Schema):
    name = fields.Str()

class AlbumSchema(Schema):
    title = fields.Str()
    release_date = fields.Date()
    artist = fields.Nested(ArtistSchema())

bowie = dict(name='David Bowie')
album = dict(artist=bowie, title='Hunky Dory', release_date=date(1971, 12, 17))

schema = AlbumSchema()
result = schema.dump(album)
pprint(result, indent=2)
# { 'artist': {'name': 'David Bowie'},
#   'release_date': '1971-12-17',
#   'title': 'Hunky Dory'}

In short, marshmallow schemas can be used to:

• Validate input data.
• Deserialize input data to app-level objects.
• Serialize app-level objects to primitive Python types. The serialized objects can then be rendered to standard formats such as JSON for use in an HTTP API.

$ pip install -U marshmallow --pre

Full documentation is available at http://marshmallow.readthedocs.io/ .

• Python >= 2.7 or >= 3.5

marshmallow has no external dependencies outside of the Python standard library, although python-dateutil is recommended for robust datetime deserialization.

A list of marshmallow-related libraries can be found at the GitHub wiki here:

https://github.com/marshmallow-code/marshmallow/wiki/Ecosystem

This project exists thanks to all the people who contribute.

You're highly encouraged to participate in marshmallow's development. Check out the Contributing Guidelines to see how you can help.

Thank you to all who have already contributed to marshmallow!

If you find marshmallow useful, please consider supporting the team with a donation. Your donation helps move marshmallow forward.

Thank you to all our backers! [Become a backer]

Support this project by becoming a sponsor (or ask your company to support this project by becoming a sponsor). Your logo will show up here with a link to your website. [Become a sponsor]

• Docs: http://marshmallow.readthedocs.io/
• Changelog: http://marshmallow.readthedocs.io/en/latest/changelog.html
• PyPI: https://pypi.python.org/pypi/marshmallow
• Issues: https://github.com/marshmallow-code/marshmallow/issues
• Donate: https://opencollective.com/marshmallow

MIT licensed. See the bundled LICENSE file for more details.