python - 反向函数返回的 'iterator object' 是什么？

Question

我正在尝试使用 reversed在列表上运行，但我在处理返回值时遇到了问题。

s=[0,1,2,3]
print(reversed(s))

这将返回这一行: <list_reverseiterator object at 0x000001488B6559A0>

我知道 reversed()函数返回一个迭代器对象。有人可以详细说明“迭代器对象”吗？

Answer 1

迭代器对象是一个对象，实际上与生成器是一样的。

来自docs :

Generators are iterators, but you can only iterate over them once. It’s because they do not store all the values in memory, they generate the values on the fly. You use them by iterating over them, either with a ‘for’ loop or by passing them to any function or construct that iterates. Most of the time generators are implemented as functions. However, they do not return a value, they yield it.

解决这个问题的方法是:

print(list(reversed(s)))

输出:

[3, 2, 1, 0]