python 中的 dict() 与 { } 哪个更好? [英] dict() vs { } in python which is better?

问题描述

我想知道，在以下两种方法中声明字典的最佳做法是什么?为什么?

I like to know, which is the best practice to declare dictionary in below 2 approaches and why?

>>>a=dict(one=2, two=3)  # {"two":3, "one":2}
>>>a={"two":3, "one":2}

推荐答案

你会相信 有人已经分析过(从性能角度).

Would you believe someone has already analyzed that (from a performance perspective).

使用 CPython 2.7，使用 dict() 创建字典最多需要 6时间更长，涉及更多的内存分配操作字面语法.使用 {} 创建字典，特别是如果您是预先填充它们，除非文字语法不适用于您案例.

With CPython 2.7, using dict() to create dictionaries takes up to 6 times longer and involves more memory allocation operations than the literal syntax. Use {} to create dictionaries, especially if you are pre-populating them, unless the literal syntax does not work for your case.

这篇关于python 中的 dict() 与 { } 哪个更好?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！