擅长:python、mysql、java
<p><code>and</code>的优先级高于<code>or</code>。你知道吗</p>
<h3>(2) </h3>
<pre><code>0 and foo() or 1 == (0 and foo()) or 1
== 0 or 1 # short-circuited, foo() never evaluated
== 1
</code></pre>
<h3>(4) </h3>
<pre><code>1 or foo() and 0 == 1 or (foo() and 0)
== 1 # short-circuited, foo() never evaluated
</code></pre>