擅长:python、mysql、java
<p>简短的回答(目前为止最短的)是:</p>
<pre><code>l = [1, 2, 3]
m = [[row - col for row in l] for col in l]
</code></pre>
<p>它使用<a href="https://docs.python.org/2/tutorial/datastructures.html#list-comprehensions" rel="nofollow noreferrer">list comprehension</a>。在</p>