擅长:python、mysql、java
<p>可以使用<a href="https://docs.scipy.org/doc/numpy-1.14.0/reference/generated/numpy.where.html" rel="nofollow noreferrer">^{<cd1>}</a>执行此操作:</p>
<pre><code>df['SKU_CB'] = np.where(df['ClosingBalance'] > 1, df['SKU'], np.nan)
</code></pre>
<p>或者,在使用<a href="https://docs.scipy.org/doc/numpy-1.14.0/reference/generated/numpy.select.html" rel="nofollow noreferrer">^{<cd2>}</a>时,第二个参数似乎有问题:</p>
<blockquote>
<p>choicelist : list of ndarrays The list of arrays from which the output elements are taken. It has to be of the same length as condlist.</p>
</blockquote>
<p>所以应该是这样</p>
<pre><code>df['SKU_CB'] = np.select(conditions, [df['SKU']], default=np.nan)
</code></pre>