擅长:python、mysql、java
<pre><code>>>> x = "Hello World!"
>>> x[2:]
'llo World!'
>>> x[:2]
'He'
>>> x[:-2]
'Hello Worl'
>>> x[-2:]
'd!'
>>> x[2:-2]
'llo Worl'
</code></pre>
<p>Python将这个概念称为“切片”,它不仅仅适用于字符串。请看<a href="https://stackoverflow.com/questions/509211/good-primer-for-python-slice-notation">here</a>以获得全面的介绍。</p>