问题描述
sort() 和 reverse() 方法在排序或反转大列表时修改列表以节省空间.提醒您它们是通过副作用操作的，它们不会返回排序或反转的列表.
以上文本可以在http://docs.python.org/2/library/stdtypes.html#mutable-sequence-types
为节省空间而修改清单"是什么意思?
What does "modify the list in place for economy of space" mean?
示例:
x = ["happy", "sad"]
y = x.reverse()
会将 None 返回到 y.那么为什么，
would return None to y. So then why does,
x.reverse()
成功反转x?
推荐答案
这意味着它不会创建列表的副本.
What this means is that it does not create a copy of the list.
为什么，x.reverse() 成功反转 x?
我不明白这个问题.它这样做是因为这就是它的设计目的(反转 x 并返回 None).
I don't understand this question. It does this because that's what it's designed to do (reverse x and return None).
请注意，sort() 和 reverse() 的对应项不会修改原始文件并返回副本.这些函数被称为 sorted() 和reversed():
Note that sort() and reverse() have counterparts that don't modify the original and return a copy. These functions are called sorted() and reversed():
In [7]: x = [1, 2, 3]
In [8]: y = list(reversed(x))
In [9]: x
Out[9]: [1, 2, 3]
In [10]: y
Out[10]: [3, 2, 1]
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