guardian-type-enforcer 4.0.5

Maximum performance runtime type enforcement using CPython C API.

🛡️ Guardian — Sub-Microsecond Runtime Type Enforcement & Access Control for Python

Guardian is a blazing-fast runtime type enforcer and data validation framework for Python 3.11+.

Unlike traditional Python validation libraries that rely on slow dictionary wrappers, getattr proxies, or __dict__ parsing, Guardian is written entirely as a native C-extension. It intercepts assignments directly at the memory level via the CPython API, delivering O(1) validation that outperforms industry standards like Pydantic (Rust).

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🚀 Performance Benchmarks

Guardian is engineered for high-throughput backend APIs and data pipelines where nanosecond performance matters. (Benchmarks run for 100,000 iterations against standard Python 3.13 on native Linux)

Operation / Library	Time (ns / op)	Relative Speed
Standard Python Function	30.61 ns	1.00x
@guard Function	80.79 ns	2.64x
Beartype Function	241.10 ns	7.88x
Standard / shield Init	653.75 ns	N/A
Pydantic v2 Init (Rust)	824.64 ns	N/A
shield Attribute Set	76.26 ns	N/A
Pydantic v2 Attribute Set	194.05 ns	N/A

Highlights

• Function decorators: @guard is ~3× faster than Beartype
• Class models: shield is ~2.5× faster than Pydantic v2 at attribute assignment

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📦 Installation

Guardian distributes pre-compiled wheels for Linux, macOS, and Windows.

pip install guardian-type-enforcer

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🛠️ Core Features

1. Guardian Dataclasses & Domain Validators

Guardian wraps the standard Python library @dataclass to provide native C-speed type enforcement with zero namespace pollution.

from guardian.dataclasses import dataclass, validator

@dataclass(frozen=True)
class DatabaseConfig:
    host: str
    port: int

    @validator("host")
    def sanitize_host(cls, value: str):
        return value.strip().lower()

config = DatabaseConfig(host="  LOCALHOST ", port=5432)
print(config.host)  # "localhost"

# ❌ Raises FrozenInstanceError
config.port = 8080

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2. shield (C-Native Data Models & Encapsulation)

from guardian.shield import Shield
from guardian._guardian_core import GuardianTypeError, GuardianAccessError

class Account(Shield):
    username: str
    _balance: float
    _total_accounts: int = 0

    def __init__(self, username: str):
        self.username = username
        self._balance = 0.0
        Account._total_accounts += 1

account = Account("Michex")
account.username = "Mike"   # OK
account.username = 123       # Raises GuardianTypeError

print(account._balance)      # Raises GuardianAccessError
Account._total_accounts = 999  # Raises GuardianAccessError

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3. @guard (Boundary Type Enforcement)

from typing import Union
from guardian import guard

@guard
def process_sensor_data(payload: dict[str, list[Union[int, float]]]) -> bool:
    return True

process_sensor_data({"sensor_A": [1, 2.5, 3]})
process_sensor_data({"sensor_A": [1, 2.5, "3.0"]})

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4. @deepguard (Local State Profiling)

from guardian import deepguard

@deepguard
def calculate_discount(price: float) -> float:
    discount: float = 0.0
    if price < 0:
        discount = "N/A"  # Type error
    return price - discount

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🧠 Advanced Usage: The Compiler

Guardian compiles complex type hints into optimized internal representations for C-level evaluation.

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🤝 Contributing

We recommend WSL 2 / Linux for development.

# Clone repository
git clone https://github.com/yourusername/guardian-type-enforcer.git
cd guardian-type-enforcer

# Create environment
uv venv --python 3.14
source .venv/bin/activate

# Install + build
uv pip install -e .
pytest tests/ -v

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📄 License

MIT License — see LICENSE file.

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🔄 Guardian Update Ledger

⚡ C-Core Memory & Profiling Optimizations

• Zero-allocation string routing using optimized CPython mappings
• PEP 667 compatibility for Python 3.13+ FrameLocalsProxy
• Read-path acceleration via native CPython attribute lookup

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🏗️ Dataclass Engine & Static Typing

• guardian.dataclasses.dataclass fully mirrors stdlib behavior
• Frozen instance compatibility layer added
• typing.dataclass_transform integration for IDE support

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🛡️ Access Control & Encapsulation

• Added @validator hook system
• Extended frame-walking protection to class-level access

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🛠️ Developer Experience

• Recommended Linux/WSL 2 build pipeline
• Adopted uv for ultra-fast environment management