inito 0.0.1b0

A Lombok-inspired boilerplate-elimination library for Python.

inito

A Lombok-inspired boilerplate-elimination library for Python. inito generates constructors, repr, equality/hashing, accessors, and fluent builders once at class-decoration time — never at instance construction or attribute-access time — so the generated classes perform like handwritten ones. Zero runtime dependencies.

Install

pip install inito

or

uv add inito

Quick start

from inito import Data


@Data
class User:
    name: str
    age: int = 0


user = User("Ada", age=30)
print(user)              # User(name='Ada', age=30)
print(user.get_name())   # Ada
user.set_age(31)

@Data also accepts options:

from inito import Data


@Data(frozen=True)
class Point:
    x: int
    y: int

@builder generates a fluent, chainable builder, and composes with @dataclass:

from dataclasses import dataclass
from inito import builder


@builder(to_builder=True)
@dataclass
class Request:
    prompt: str
    temperature: float = 0.7


request = Request.builder().prompt("hello").build()
revised = request.to_builder().temperature(0.9).build()

Status

Implemented today: @Data (constructor, __repr__, __eq__, __hash__, getters, setters), @Getter (getters only), @Setter (setters only), @NoArgsConstructor (no-argument constructor using field defaults), @AllArgsConstructor (constructor only, every field), @RequiredArgsConstructor (constructor only accepting required fields), @Builder/builder (fluent builder, to_builder=True support), @ToString (__repr__ only — pairs well with @Builder for a readable repr without pulling in @Data's constructor/eq/hash/accessors), and @EqualsAndHashCode (__eq__/__hash__ only).

All of inito.md's Initial Features (v1) are now implemented. See docs/performance.md for benchmarks against handwritten classes, dataclasses, and attrs. See TASKS.md for what's left: docs, CI hardening, and release.

Known limitation: static type checkers don't see generated members yet

Every generated member (get_x, set_x, .builder(), .to_builder(), the generated constructor's parameters, ...) is attached to your class via setattr at decoration time — real attributes at runtime, but invisible to mypy/pyright today, since neither tool has a plugin for inito yet. Your code will run correctly; mypy --strict/pyright will flag those accesses as unknown attributes in the meantime. attrs and Pydantic hit the same problem and solved it with dedicated mypy plugins — that's tracked as a future initiative (see TASKS.md Phase 17), not required for this release.

Known limitations: frozen dataclasses and self-referential fields

Stacking any inito constructor-generating decorator (@Data, @Builder, @AllArgsConstructor, ...) with @dataclass(frozen=True) — in either order — raises dataclasses.FrozenInstanceError. This is expected, not a bug: the generated __init__/build() assign fields with plain self.x = value, which correctly respects the frozen class's blocking __setattr__ rather than silently bypassing the immutability you asked for. If you want inito's own frozen-style behavior, use @Data(frozen=True) (which just omits setters) instead of also stacking @dataclass(frozen=True).

Self-referential type hints (e.g. a linked-list next: Node) also aren't supported: inito resolves annotations eagerly, once, at decoration time — before the class's own name is bound in its module's globals — so a forward reference to the class currently being decorated can't resolve. Forward references to any other, already-defined class work normally.

Contributing

See CONTRIBUTING.md.

License

MIT — see LICENSE.