Auto-Freeze

The @auto_freeze decorator enforces immutability after __init__ completes — no frozen=True dataclass boilerplate needed.

Usage

Apply to any class:

• @auto_freeze — Freezes the entire instance
• @auto_freeze() — Equivalent, explicit parens form
• @auto_freeze(attrs=["_id"]) — Selectively freeze specific attributes only

After __init__ returns, any attempt to assign a frozen attribute raises CantModifyImmutableAttributeError. The decorator handles __init__ nesting (inheritance chains) and skips abstract classes.

When to use

auto_freeze is an alternative to inheriting from ValueObject.

• If your class already has its own base class and you only need immutability — without value-based equality or hashing — prefer @auto_freeze.
• If you also need equality-by-value, use the ValueObject base class instead.

Both are optional; you can use neither.

Design

auto_freeze injects a __setattr__ override and a freeze flag. It detects existing custom __setattr__ implementations and avoids double-wrapping.