Python使用的字符串比较技术 [英] String Comparison Technique Used by Python

问题描述

我想知道Python如何进行字符串比较，更具体地说，当使用小于（<）或大于（>）的符号时，如何确定结果。

I'm wondering how Python does string comparison, more specifically how it determines the outcome when a less than (<) or greater than (>) sign is used.

例如，如果我把print（'abc'<'bac'）我成真。我理解它比较字符串中的相应字符，但是它不清楚为什么有更多，由于缺乏一个更好的术语，权重放在事实上a小于b（第一个位置）在第一个字符串，而不是

For instance if I put print('abc' < 'bac') I get true. I understand that it compares corresponding characters in the string, however its unclear as to why there is more, for lack of a better term, "weight" placed on the fact that a is less than b (first position) in first string rather than the fact that a is less than b in the second string (second position).

推荐答案

从文档：

比较使用字典
排序：首先比较前两个项目
，如果它们不同，则
确定
比较的结果;如果它们相等，则接下来两个项目的
被比较，因此
打开，直到序列是
耗尽。

The comparison uses lexicographical ordering: first the first two items are compared, and if they differ this determines the outcome of the comparison; if they are equal, the next two items are compared, and so on, until either sequence is exhausted.

还有：

字符串的词典排序
使用单个
字符的ASCII排序

Lexicographical ordering for strings uses the ASCII ordering for individual characters.

例如：

>>> 'abc' > 'bac'
False
>>> ord('a'), ord('b')
(97, 98)

a 一旦发现小于 b <>，则返回结果 False / code>。其他项目没有比较（正如你可以看到的第二个项目： b > a 是 True ）。

The result False is returned as soon as a is found to be less than b. The further items are not compared (as you can see for the second items: b > a is True).

这篇关于Python使用的字符串比较技术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！