Clean Code in Python

Slots

When a class defines the __slots__ attribute, it can contain all the attributes that the class expects and no more.

Trying to add extra attributes dynamically to a class that defines __slots __ will result in an AttributeError. By defining this attribute, the class becomes static, so it will not have a __dict__ attribute where you can add more objects dynamically.

How, then, are its attributes retrieved if not from the dictionary of the object? By using descriptors. Each name defined in a slot will have its own descriptor that will store the value for retrieval later:

class Coordinate2D:    __slots__ = ("lat", "long")    def __init__(self, lat, long):        self.lat = lat        self.long = long    def __repr__(self): return f"{self.__class__.__name__}({self.lat}, ...