Technically not a built-in data type, as you have to import them from the enum module, but definitely worth mentioning, are enumerations. They were introduced in Python 3.4, and though it is not that common to see them in professional code (yet), I thought I'd give you an example anyway.
The official definition goes like this: "An enumeration is a set ofsymbolicnames (members) bound to unique, constant values. Within an enumeration, the members can be compared by identity, and the enumeration itself can be iterated over."
Say you need to represent traffic lights. In your code, you might resort to doing this:
>>> GREEN = 1 >>> YELLOW = 2 >>> RED = 4 >>> TRAFFIC_LIGHTS = (GREEN, YELLOW, RED) >>> # or with a dict >>> traffic_lights = {'GREEN': 1, 'YELLOW': 2, 'RED': 4}
There's nothing special about the preceding code. It's something, in fact, that is very common to find. But, consider doing this instead:
>>> from enum import Enum...