擅长:python、mysql、java
<p>更改:</p>
<pre><code>if (stockdata['noise']!= 0):
stockdata['efratio']= (stockdata['signal']/stockdata['noise'])
else :
stockdata['efratio']= 1
</code></pre>
<p>收件人:</p>
<pre><code>import numpy as np
stockdata['efratio'] = np.where(stockdata['noise'] != 0,
stockdata['signal'] / stockdata['noise'], 1)
</code></pre>
<p>发生的情况如下:</p>
<blockquote>
<p><code>where(condition, [x, y])</code></p>
<p>Return elements, either from <code>x</code> or <code>y</code>, depending on <code>condition</code>.</p>
</blockquote>