Sequence

In python3, There are three basic sequence types: lists, tuples, and range objects.

抽象基类Sequence

在python3中确实有class Sequence的定义, 位于文件 cpython/Lib/_collections_abc.py, 并且是抽象基类(abstract base class, abc)

_images/sequence_uml.png

从上面的UML图可得：

  1. list, tuple, range都是iterable，可以用于“for loop”
  2. Iterator, Iterable, Sequence都是抽象基类(abstract base class, abc)

Features

  1. ordered

record element position or order of insertion. support indexing, slicing, or other sequence-like behavior.