overrides

library7.7.0pypypi✓ verified 52d ago

The `overrides` library (v7.7.0) provides a Python decorator `@override` to ensure that a method in a subclass correctly overrides a method from its superclass. It also includes `EnforceOverrides` for metaclass-level checks and `@final` to prevent methods from being overridden. The library focuses on improving the safety and experience of creating class hierarchies by catching common errors at class creation time, such as signature mismatches or accidental non-overrides. It has a regular release cadence, with several minor and patch releases in the past year.

testing

pip install overrides

github ↗package ↗

Install & Compatibility

Where this runs

tested against v7.7.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.925 runs

installs and imports cleanly · install 0.0s · import 0.036s · 17.9MB

glibc

py 3.10–3.925 runs

installs and imports cleanly · install 1.5s · import 0.032s · 18MB

16MB installed

● package 16MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

override

✓ from overrides import override

This is the recommended alias for the decorator since version 7.3.0.

overrides

✓ from overrides import overrides

The original name of the decorator, still functional but `@override` is preferred.

EnforceOverrides

✓ from overrides import EnforceOverrides

✗ from overrides import overrides

This is a metaclass, not a decorator, used to enforce `@override` usage.

final

✓ from overrides import final

Use `typing.final` directly for Python 3.11+; `overrides.final` provides a backport for older versions.

This quickstart demonstrates how to use the `@override` decorator with the `EnforceOverrides` metaclass. The `Animal` class defines methods, and `Dog` subclasses it, using `@override` to explicitly mark overridden methods. If `EnforceOverrides` is used, methods intended to override a superclass method *must* use the `@override` decorator, otherwise a `TypeError` will be raised at class creation time. The library also automatically copies docstrings from the overridden method.

from overrides import override, EnforceOverrides class Animal(EnforceOverrides): def make_sound(self) -> str: raise NotImplementedError def eat(self) -> str: return "Eating generic food" class Dog(Animal): @override def make_sound(self) -> str: return "Woof!" # No @override needed if not overriding a method, or if EnforceOverrides is not used. def fetch(self) -> str: return "Fetching the ball" # Example of usage dog = Dog() print(dog.make_sound()) print(dog.eat()) # This would raise TypeError if @override was missing on make_sound and EnforceOverrides was used. # class Cat(Animal): # def make_sound(self) -> str: # Missing @override, would fail with EnforceOverrides # return "Meow!"

Debug

Known issues

breakingIn version 7.0.0, the library changed how it handles `final` magic methods and assertion failures. Magic methods (e.g., `__eq__`, `__init__`) marked as `@final` that are accidentally overridden now raise `TypeError` instead of `AssertionError`. Similarly, assertion errors originating from the `EnforceOverrides` metaclass have been changed to `TypeErrors`. This may break existing tests or error handling code that specifically caught `AssertionError`.

fix

Update exception handling to catch `TypeError` instead of `AssertionError` for issues related to `EnforceOverrides` or `final` magic method overrides.

affects: 7.0.0 and later

gotchaVersions prior to 7.6.0 might experience issues with Python 3.12 due to changes in bytecode handling. This could lead to unexpected behavior or runtime errors on Python 3.12 environments.

fix

Upgrade to `overrides` version 7.6.0 or newer to ensure compatibility and correct bytecode handling with Python 3.12.

affects: <7.6.0

gotchaWhen combining `@override` with other method decorators like `@classmethod` or `@staticmethod`, the `@classmethod` or `@staticmethod` decorator must always be applied *before* `@override`. Incorrect order will lead to unexpected behavior or errors.

fix

Ensure `@classmethod` or `@staticmethod` is the outermost decorator, followed by `@override`. Example: `@classmethod
@override
def my_method(cls, ...):`

affects: All versions

deprecatedThe original decorator name `@overrides` (plural) is still functional, but `@override` (singular) was introduced in version 7.3.0 as an alias and is now the officially recommended decorator name, aligning with common usage and `typing.override`.

fix

Prefer using `from overrides import override` and the `@override` decorator for new code. Update existing code to use `@override` for consistency.

affects: 7.3.0 and later

gotchaIf a base class inherits from `EnforceOverrides`, any method in a subclass that is intended to override a superclass method *must* be explicitly decorated with `@override` (or `@overrides`). Failing to do so will result in a `TypeError` at class definition time, preventing subtle bugs caused by method signature changes in parent classes.

fix

Always decorate methods in subclasses with `@override` if they are meant to override a method from a base class that uses `EnforceOverrides`.

affects: All versions

gotchaPython 3.12 introduced a standard `typing.override` decorator (PEP 698) for static type checkers. The `overrides` library's `@override` provides *runtime* validation and docstring inheritance, which is distinct from `typing.override`'s static analysis purpose. Using both might be confusing but they serve different roles.

fix

Understand the difference: `overrides.override` provides runtime checks and features, while `typing.override` is purely for static analysis. Choose based on whether you need runtime enforcement or only static type checking.

affects: 3.12 and later

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'overrides'

The 'overrides' library is not installed in the Python environment.

fix

Install the 'overrides' library using pip: 'pip install overrides'.

ImportError: cannot import name 'override' from 'overrides'

The 'override' decorator is not available in the 'overrides' module.

fix

Ensure you are using the correct import statement: 'from overrides import override'.

TypeError: 'override' object is not callable

The 'override' decorator is being used incorrectly, possibly without parentheses.

fix

Use the 'override' decorator with parentheses: '@override()'.

AttributeError: module 'overrides' has no attribute 'EnforceOverrides'

The 'EnforceOverrides' metaclass is not available in the 'overrides' module.

fix

Ensure you are using the correct import statement: 'from overrides import EnforceOverrides'.

SyntaxError: unexpected EOF while parsing

The 'override' decorator is used without the '@' symbol.

fix

Use the 'override' decorator with the '@' symbol: '@override'.

Upgrade

Version history

7.7.0latest on PyPI

Audit

Dependencies

No dependency data recorded yet.

Agent activity

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Resources

githubhttps://github.com/mkorpela/overrides ↗

packagehttps://pypi.org/project/overrides/ ↗