擅长:python、mysql、java
<p>您可以通过将<code>groupby</code>与<code>transform</code>一起使用,然后将条件与<code>np.where</code>一起应用来实现:</p>
<pre><code>df['Rating']=df.groupby('Location')['Date'].transform('count')
df['Rating']=np.where(df['Rating']<150,1,np.where(df['Rating']<200,2,np.where(df['Rating']<250,3,np.where(df['Rating']<300,4,np.where(df['Rating']==300,5,'')))))
</code></pre>