擅长:python、mysql、java
<p>你能试试使用shift和groupby吗?一旦前一行的所有操作都是直行。在</p>
<pre><code>table2['previous'] = table2['close'].groupby('symbol').shift(1)
table2
date symbol close atr previous
1990-01-01 A 24 2 NaN
B 72 7 NaN
C 40 3.4 NaN
1990-01-02 A 21 1.5 24
B 65 6 72
C 45 4.2 40
1990-01-03 A 19 2.5 21
B 70 6.3 65
C 51 5 45
</code></pre>