擅长:python、mysql、java
<p><a href="https://docs.python.org/3/reference/expressions.html#yieldexpr" rel="nofollow">yield expression</a>的结果是<a href="https://docs.python.org/3/reference/expressions.html#generator.send" rel="nofollow">generator.send()</a>函数发送的值,<code>next(gen)</code>相当于{<cd2>}。因此,<code>new</code>每次调用<code>next()</code>时都会收到值<code>None</code>。在</p>
<p>如果您改为这样做:</p>
<pre><code>gen = func()
print(next(gen)) # gets the first value of 'output'
print(next(gen)) # send in None, get None back
print(gen.send(10)) # send in 10, get 10 back
print(gen.send(20)) # send in 20, get 20 back
</code></pre>
<p>您将得到以下输出:</p>
^{pr2}$