擅长:python、mysql、java
<p>这实际上会增加内存占用。每次对一个列表进行切片时,除了旧列表之外,还会得到一个新列表。在</p>
<p>例如:</p>
<pre><code>l = [1, 2, 3, 4] # great, we have 4 references to objects in this list
l2 = l[:2] # ok, now we have an additional list with 2 more references
</code></pre>
<p>你真正想做的是把原始数据分块读入。在</p>