擅长:python、mysql、java
<p>假设您的数据是按日期排序的,您可以使用groupby和shift</p>
<pre><code>df['LastPrice'] = (
df.groupby('Ticker')
.apply(lambda x: x.Price.shift())
.reset_index(0, drop=True)
)
Date Ticker Price LastPrice
0 2019-03-21 AAPL 100 NaN
1 2019-03-21 GOOG 101 NaN
2 2019-03-21 IBM 102 NaN
3 2019-03-25 AAPL 90 100.0
4 2019-03-25 GOOG 91 101.0
5 2019-03-25 IBM 92 102.0
6 2019-03-27 AAPL 110 90.0
7 2019-03-27 GOOG 111 91.0
8 2019-03-27 IBM 112 92.0
</code></pre>