Python Native Serialization
Python native serialization is the Python-only wire mode selected with xlang=False. Use it when
every writer and reader is Python and the payload should follow Python's object model instead of
the portable xlang type system.
Use Xlang Serialization, the default Python mode, when bytes must be read by Java, C++, Go, Rust, JavaScript/TypeScript, C#, Swift, Dart, Scala, Kotlin, or another non-Python Fory implementation.
When To Use Native Serialization
Use native serialization when:
- A payload is produced and consumed only by Python applications.
- You are replacing
pickleorcloudpicklefor Python-only object graphs. - The data model includes functions, lambdas, local classes, methods, or Python reduction hooks.
- The graph can contain shared objects or cycles that need Python reference tracking.
- You need pickle protocol 5-style out-of-band buffers for large Python data objects.
Native mode can serialize Python-specific values such as global functions, local functions, lambdas,
local classes, methods, and objects customized with __getstate__, __setstate__, __reduce__,
or __reduce_ex__. Those values are not valid xlang payloads.
Create a Native-Mode Fory Instance
Create Fory with xlang=False:
import pyfory
fory = pyfory.Fory(xlang=False, ref=False, strict=True)
Keep strict=True for registered, trusted type surfaces. Use strict=False only when native-mode
payloads need dynamic Python types such as functions, local classes, or objects reconstructed by
reduction hooks.
Common Usage
import pyfory
fory = pyfory.Fory(xlang=False, ref=True, strict=False)
data = fory.dumps({"name": "Alice", "age": 30, "scores": [95, 87, 92]})
print(fory.loads(data))
from dataclasses import dataclass
@dataclass
class Person:
name: str
age: int
person = Person("Bob", 25)
data = fory.dumps(person)
print(fory.loads(data)) # Person(name='Bob', age=25)
Use dumps/loads for pickle-style APIs, or serialize/deserialize when matching the xlang
API shape in code that switches modes explicitly.
Security And Dynamic Types
Native mode can reconstruct Python objects that execute import and construction logic during deserialization. Treat untrusted native-mode bytes the same way you would treat untrusted pickle bytes.
- Keep
strict=Truewhen deserializing data that should contain only registered or built-in types. - Use
strict=Falseonly for trusted payloads that require dynamic Python classes or functions. - Provide a
policy=deserialization policy when dynamic types are required but the accepted type surface should still be restricted. - Do not use xlang/native mode choice as a security control. Apply strict mode, policies, registration, and resource limits based on the payload source.
Python-specific values and hooks
See Functions, Classes, and Methods for callable and type values, then Serialization Hooks for reduction, state, construction, and pickle/cloudpickle migration.
References And Cycles
Enable ref=True when object identity, shared references, or cycles must round-trip:
import pyfory
fory = pyfory.Fory(xlang=False, ref=True, strict=True)
node = {}
node["self"] = node
data = fory.dumps(node)
decoded = fory.loads(data)
assert decoded["self"] is decoded
Disable reference tracking for value-shaped payloads that do not need identity preservation. It keeps the payload smaller and the hot path simpler.
Out-of-Band Buffers
Python native mode can use pickle protocol 5-style out-of-band buffers for large binary payloads and data structures backed by external memory:
import pickle
import pyfory
data = b"Large binary data"
pickle_buffer = pickle.PickleBuffer(data)
buffer_objects = []
fory = pyfory.Fory(xlang=False, ref=True, strict=False)
serialized = fory.dumps(pickle_buffer, buffer_callback=buffer_objects.append)
buffers = [obj.getbuffer() for obj in buffer_objects]
decoded = fory.loads(serialized, buffers=buffers)
assert bytes(decoded.raw()) == data
Use this when the payload stays in Python and large buffers should avoid extra copies. See Out-of-Band Serialization.
Native And Xlang Comparison
| Requirement | Use native serialization | Use xlang serialization |
|---|---|---|
| Python-only payloads | Yes | Optional |
| Non-Python readers or writers | No | Yes |
| Functions, lambdas, local classes | Yes | No |
__reduce__ / __getstate__ object hooks | Yes | No |
| Pickle/cloudpickle replacement | Yes | No |
| Portable type mapping across languages | No | Yes |
Performance Comparison
import pyfory
import pickle
import timeit
fory = pyfory.Fory(xlang=False, ref=True, strict=False)
obj = {f"key{i}": f"value{i}" for i in range(10000)}
print(f"Fory: {timeit.timeit(lambda: fory.dumps(obj), number=1000):.3f}s")
print(f"Pickle: {timeit.timeit(lambda: pickle.dumps(obj), number=1000):.3f}s")
Troubleshooting
Another language cannot read the payload
The writer is using native serialization. Rebuild it with xlang=True, register portable schemas
on every peer, and avoid Python-only values such as lambdas or local classes.
A dynamic class or function fails to deserialize
Use strict=False for trusted payloads and provide a deserialization policy= when only selected
dynamic types should be accepted.
A cycle does not round-trip
Create the Fory instance with ref=True.
A value depends on pickle hooks
Keep the payload in native mode. Xlang mode does not execute Python __reduce__,
__reduce_ex__, __getstate__, or __setstate__ object reconstruction hooks.
Related Topics
- Xlang Serialization - Cross-language Python payloads
- Configuration - Python
Foryoptions - Out-of-Band Serialization - Zero-copy buffer support
- Configuration - Deserialization policies