擅长:python、mysql、java
<p>Python3更改了<code>/</code>运算符的行为。它过去依赖于所使用的类型(即<code>integer / integer</code>是整数除法,如果其中一个操作数是float,则得到float除法)。在</p>
<p>Python增强建议<a href="https://www.python.org/dev/peps/pep-0238/#motivation" rel="nofollow noreferrer">PEP-0238</a>中解释了更改的基本原理:</p>
<blockquote>
<p>The correct work-around is subtle: casting an argument to float() is wrong if it could be a complex number; adding 0.0 to an argument doesn't preserve the sign of the argument if it was minus zero. The only solution without either downside is multiplying an argument (typically the first) by 1.0. This leaves the value and sign unchanged for float and complex, and turns int and long into a float with the corresponding value.</p>
</blockquote>