Python 3 Deep Dive Part 4 Oop High Quality Guide

def my_meta(name, bases, dct): dct['version'] = 1.0 return type(name, bases, dct) class MyClass(metaclass=my_meta): pass

class ValidateMixin: def process(self): print("Validating") super().process() python 3 deep dive part 4 oop high quality

from collections.abc import Sized class MyContainer: def (self): return 10 def my_meta(name, bases, dct): dct['version'] = 1

class Base: def process(self): print("Base") class LogMixin: def process(self): print("Logging start") super().process() print("Logging end") dct): dct['version'] = 1.0 return type(name

from abc import ABC, abstractmethod class Stream(ABC): @abstractmethod def read(self): pass

class BadCircle: def __init__(self, radius): self._radius = radius def get_radius(self): return self._radius def set_radius(self, value): if value < 0: raise ValueError("Radius cannot be negative") self._radius = value :

def __set__(self, instance, value): if value <= 0: raise ValueError("Must be positive") instance.__dict__[self.name] = value class Order: quantity = PositiveNumber() price = PositiveNumber()