摘要： 《Python for Beginners》为LearnStreet上的Python入门课程。本节主要学习内容为字符串。一、基本概念1. Indexing - References a specific element of a sequence. The first element in a sequence is found at the index 0. To use a single element, call it with [], like this: variable_name[index].首元素的索引值为0。2. Negative Indexing - This allows 阅读全文