Pyeo is an advanced static analysis tool tailored specifically to enforce the principles advocated by Elegant Objects (elegantobjects.org) in Python projects. It serves as a quality control instrument to ensure that your Python code adheres to the core tenets of elegance, simplicity, and maintainability.
The project is inspired by the team that made fun of me because of the lego build. STT lambda ❤️️
pip install eo-styleguideSimple example of usage:
from typing import Protocol, final
import attrs
class House(Protocol):
def area(self) -> int: ...
@final
@attrs.define(frozen=True)
class HttpHouse(House):
def area(self) -> int:
return 10mypy file.py && flake8 file.py- Principles
-
No ORM or ActiveRecord (why? and why?)
Mypy helps prevent AttributeError and other type-related errors by providing
static type checking for Python code. It allows specifying variable types,
function arguments, and return types to catch potential type issues before the
program runs. By using Mypy, developers can identify and fix problems related
to attribute access and other type mismatches, leading to improved code
quality and easier maintenance.
Example:
class Employee(object):
def __init__(self, user_id: int):
self._user_id = user_id
def get_by_id(user_id: int) -> Employee:
if user_id < 0:
return None
return Employee(user_id)Mypy return next violation:
error: Incompatible return value type (got "None", expected "Employee") [return-value]
So, we must use typing.Optional or | (union) operator.
It's works:
def get_by_id(user_id: int) -> Optional[Employee]: ...
def get_by_id(user_id: int) -> Employee | None: ...
You can use @attrs.define for skip this. It decorator create ctor for your
classes automatically. However, we implement check that your primary and
secondary ctors not contain code, with the exception of attributes assingment.
Please check CodeFreeCtorVisitor.
Actually we realize functional for to prohibit the use of @property and
@setter method decorators. You can use @attrs.define(frozen=True) in order
to make an object immutable.
Prohibit the use of @property decorator not protect from evil of getters,
so if you can ideas how we can implement more complex check,
create issue please.
attrs.define(frozen=True) is a parameter used in the attrs library to create
classes with attributes that cannot be modified after the instance is created
(i.e., immutable or "frozen" classes).
The attrs library allows defining classes
using the @attr.s decorator or by explicitly calling the attr.define
function, and frozen=True is one of the parameters for specifying attribute
behavior in the class.
When you use attrs.define(frozen=True) for a class, all its attributes become
read-only after the instance is created, making the class "frozen" or
"immutable," preventing any changes to its attribute values.
We check you class name not contain -er or (C|c)lient suffix by check in
NoErNamesFeature
TODO
TODO
Prohibit next function calls:
isinstancetypeissubclasshasattr
In Python, typing.Protocol is a class introduced in Python 3.8 as part of the
typing module. It is used to define structural subtyping or "duck typing" for
classes, which allows you to create interfaces without using explicit inheritance.
flake8-override plugin check that all of public class methods has protocol.
TODO
Detect using ORM or ActiveRecord tools on project by design/code review
Each class must be typing.final.
Check by flake8-final