msgspec

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msgspec is a fast and friendly serialization library for Python, supporting both JSON_ and MessagePack_. It integrates well with Python's type annotations_, providing ergonomic (and performant!) schema validation.

Define your message schemas using standard Python type annotations.

.. code-block:: python

>>> from typing import Optional, Set

>>> import msgspec

>>> class User(msgspec.Struct):
...     """A new type describing a User"""
...     name: str
...     groups: Set[str] = set()
...     email: Optional[str] = None

Encode messages as JSON_ or MessagePack_.

.. code-block:: python

>>> alice = User("alice", groups={"admin", "engineering"})

>>> alice
User(name='alice', groups={"admin", "engineering"}, email=None)

>>> msg = msgspec.json.encode(alice)

>>> msg
b'{"name":"alice","groups":["admin","engineering"],"email":null}'

Decode messages back into Python types (with optional schema validation).

.. code-block:: python

>>> msgspec.json.decode(msg, type=User)
User(name='alice', groups={"admin", "engineering"}, email=None)

>>> msgspec.json.decode(b'{"name":"bob","groups":[123]}', type=User)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
msgspec.ValidationError: Expected `str`, got `int` - at `$.groups[0]`

msgspec is designed to be as performant as possible, while retaining some of the nicities of validation libraries like pydantic_. For supported types, encoding/decoding a message with msgspec can be ~2-40x faster than alternative libraries.

.. image:: https://github.com/jcrist/msgspec/raw/main/docs/source/_static/bench-1.png :target: https://jcristharif.com/msgspec/benchmarks.html

See the documentation <https://jcristharif.com/msgspec/>__ for more information.

LICENSE

New BSD. See the License File <https://github.com/jcrist/msgspec/blob/main/LICENSE>_.

.. _type annotations: https://docs.python.org/3/library/typing.html .. _JSON: https://json.org .. _MessagePack: https://msgpack.org .. _pydantic: https://pydantic-docs.helpmanual.io/

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