使用卷曲大括号进行初始化(Use curly braces to initialize a Set in Python)

使用卷曲大括号进行初始化(Use curly braces to initialize a Set in Python)

我正在学习python，我有一个关于初始化集的新手问题。 通过测试，我发现一个集合可以像这样初始化：

my_set = {'foo', 'bar', 'baz'}

这样做有什么不利之处，而不是标准的方式：

my_set = set(['foo', 'bar', 'baz'])

还是只是一个风格的问题？

I'm learning python, and I have a novice question about initializing sets. Through testing, I've discovered that a set can be initialized like so:

my_set = {'foo', 'bar', 'baz'}

Are there any disadvantages of doing it this way, as opposed to the standard way of:

my_set = set(['foo', 'bar', 'baz'])

or is it just a question of style?

最满意答案

set literal语法有两个明显的问题：

my_set = {'foo', 'bar', 'baz'}

Python 2.7之前不可用

没有办法使用该语法来表达一个空集（使用{}创建一个空的dict）

那些对你来说可能或可能不重要。

文档的这一部分概述了这种语法。

There are two obvious issues with the set literal syntax:

my_set = {'foo', 'bar', 'baz'}

It's not available before Python 2.7

There's no way to express an empty set using that syntax (using {} creates an empty dict)

Those may or may not be important to you.

The section of the docs outlining this syntax is here.