擅长:python、mysql、java
<p>使用<a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.where.html" rel="nofollow noreferrer">numpy.where</a>表示如果ColumnA=x,那么ColumnB=y else ColumnB=ColumnB</em>:</p>
<pre><code>df['rating'] = np.where(df['line_race']==0, 0, df['rating'])
</code></pre>