擅长:python、mysql、java
<p>如果要使用<code>for</code>循环:</p>
<pre><code>df = pd.DataFrame(mydata)
mylist = df.index[df['treatment'] != ''].tolist()
</code></pre>
<p>现在我们减去<code>year</code>值</p>
<pre><code>re_list= []
for index,row in df.iterrows():
if index > min(mylist):
m = [i for i in mylist if i <= index]
re_list.append(df.iloc[index]['year'] - df.iloc[max(m)]['year'])
else:
re_list.append(0)
df['Result'] = re_list
</code></pre>