PySerde: Serialization for Dataclasses

0.31.2 · active · verified Sun Apr 12

PySerde is a Python serialization/deserialization library built on top of dataclasses, inspired by Rust's Serde. It allows for declarative definition of data structures and automatically generates serialization and deserialization functions for various formats like JSON, YAML, TOML, and MessagePack. Currently at version 0.31.2, it maintains an active release cadence with frequent bug fixes and minor feature additions.

Warnings

breaking PySerde version 0.31.2 and later requires Python 3.10 or newer. Attempting to install or use these versions on older Python interpreters will result in an installation error.
Fix: Upgrade your Python interpreter to 3.10+ to use the latest versions of pyserde.
gotcha To use serialization/deserialization for specific formats (e.g., YAML, TOML, faster JSON backends like `orjson`), you must install `pyserde` with the corresponding extras. The base `pip install pyserde` only includes JSON support via Python's standard `json` library.
Fix: Install `pyserde` with the necessary extras, e.g., `pip install 'pyserde[json,yaml,orjson]'`.
gotcha The `@serde` decorator is designed to be applied to `dataclasses.dataclass` (or `attrs` classes when using `serde_attrs`). It will not work on plain Python classes, as it relies on the metadata and structure provided by dataclasses.
Fix: Ensure your classes are defined as dataclasses (or `attrs` classes) before applying `@serde`.
gotcha Advanced field options such as `skip_if_none`, `skip_if_default`, `flatten`, `skip_serializing`, and `skip_deserializing` were introduced in versions 0.29.0 and 0.30.0. If you rely on these specific features, ensure your `pyserde` installation is version 0.30.0 or later.
Fix: Upgrade `pyserde` to 0.30.0 or later to utilize all advanced field customization options.

Install

pip install pyserde Base installation
pip install 'pyserde[json,yaml,toml]' # Install with common backends Installation with optional backends

Imports

serde
```
from serde import serde
```
field
```
from serde import field
```
to_json
```
from serde.json import to_json
```
from_json
```
from serde.json import from_json
```

Quickstart

Decorate a dataclass with `@serde` to enable serialization and deserialization. Use format-specific functions like `to_json` and `from_json` from `serde.json`. The `@serde` decorator also adds `to_dict()` and `from_dict()` methods directly to the class for generic dictionary conversion.

from dataclasses import dataclass
from serde import serde, field
from serde.json import to_json, from_json

@serde
@dataclass
class User:
    name: str
    age: int = field(default=30)
    email: str | None = None

# Create an instance
user_instance = User(name="Alice", email="alice@example.com")

# Serialize to JSON string
json_string = to_json(user_instance)
print(f"Serialized JSON: {json_string}")

# Deserialize from JSON string
deserialized_user = from_json(User, json_string)
print(f"Deserialized User: {deserialized_user}")

# The @serde decorator also adds to_dict() and from_dict() methods directly to the class
user_dict = user_instance.to_dict()
print(f"Converted to dict: {user_dict}")

another_user = User.from_dict({"name": "Bob", "age": 25, "email": "bob@example.com"})
print(f"Created from dict: {another_user}")

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