<p>下面是答案,使用列表理解</p>
<pre><code>>>> [x[:3] for x in a[:3]]
[[1, 3, 2], [4, 9, 8], [7, 5, 6]]
</code></pre>
<p>左侧部分:</p>
<pre><code>[x[0:3] for x in a[0:3]]
[x[0:3] for x in a[3:6]]
[x[0:3] for x in a[6:9]]
</code></pre>
<p>中段:</p>
<pre><code>[x[3:6] for x in a[0:3]]
[x[3:6] for x in a[3:6]]
[x[3:6] for x in a[6:9]]
</code></pre>
<p>右侧部分:</p>
<pre><code>[x[6:9] for x in a[0:3]]
[x[6:9] for x in a[3:6]]
[x[6:9] for x in a[6:9]]
</code></pre>
<p><code>a[i:j]</code>取从索引i到j-1的直线
<code>x[i,j]</code>取所述行的索引i到j-1的元素</p>
<p>要创建“扁平”列表,请使用pwnsauce注释中的输入:</p>
<p>左侧部分:</p>
<pre><code>[x for b in [x[0:3] for x in a[0:3]] for x in b]
[x for b in [x[0:3] for x in a[3:6]] for x in b]
[x for b in [x[0:3] for x in a[6:9]] for x in b]
</code></pre>
<p>中段:</p>
<pre><code>[x for b in [x[3:6] for x in a[0:3]] for x in b]
[x for b in [x[3:6] for x in a[3:6]] for x in b]
[x for b in [x[3:6] for x in a[6:9]] for x in b]
</code></pre>
<p>右侧部分:</p>
<pre><code>[x for b in [x[6:9] for x in a[0:3]] for x in b]
[x for b in [x[6:9] for x in a[3:6]] for x in b]
[x for b in [x[6:9] for x in a[6:9]] for x in b]
</code></pre>