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marshmallow: simplified object serialization

.. image:: :target: :alt: Latest version

.. image:: :target: :alt: Build status

.. image:: :target: :alt: Documentation

.. image:: :target: :alt: code style: black

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

.. code-block:: python

from datetime import date
from pprint import pprint

from marshmallow import Schema, fields

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.

Get It Now


$ pip install -U marshmallow


Full documentation is available at .


  • Python >= 3.5


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



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!

.. image:: :target: :alt: Contributors


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_]

.. _Become a backer:

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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_]

.. _Become a sponsor:

.. image:: :target: :alt: Sponsors

.. image:: :target: :alt: Become a sponsor

Professional Support

Professionally-supported marshmallow is now available through the Tidelift Subscription <>_.

Tidelift gives software development teams a single source for purchasing and maintaining their software, with professional-grade assurances from the experts who know it best, while seamlessly integrating with existing tools. [Get professional support_]

.. _Get professional support:

.. image:: :target: :alt: Get supported marshmallow with Tidelift

Security Contact Information

To report a security vulnerability, please use the Tidelift security contact <>_. Tidelift will coordinate the fix and disclosure.

Project Links


MIT licensed. See the bundled LICENSE <>_ file for more details.

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