擅长:python、mysql、java
<p>您可以使用<a href="http://docs.scipy.org/doc/numpy/reference/generated/numpy.where.html" rel="nofollow">np.where</a>:</p>
<pre><code>import numpy as np
df['interestingness'] = np.where(df.isActive, df.changePct * df.alivePct, 0)
</code></pre>
<p>对于1D数组,<code>np.where(condition, A, B)</code>是向量化的等价物</p>
^{pr2}$
<hr/>
<p>Pandas还提供了一个<a href="http://pandas.pydata.org/pandas-docs/dev/generated/pandas.Series.where.html#pandas.Series.where" rel="nofollow">Series.where</a>方法,您可以使用:</p>
<pre><code>df['interestingness'] = (df.changePct * df.alivePct).where(df.isActive, 0)
</code></pre>