擅长:python、mysql、java
<p>用途:</p>
<pre><code>df.set_index('date')\
.groupby(['name','account'], as_index=False, group_keys=False)\
.apply(lambda x: x.reindex(pd.date_range(x.index.min(),
x.index.max(), freq='D'))
.ffill())\
.reset_index()
</code></pre>
<p>输出:</p>
<pre><code> index name account points
0 2014-02-02 Fred g21 17
1 2014-02-03 Fred g21 17
2 2014-02-04 Fred g21 17
3 2014-02-05 Fred g21 17
4 2014-02-06 Fred g21 17
5 2014-02-07 Fred g21 17
6 2014-02-08 Fred g21 19
7 2014-02-07 Fred g52 21
8 2014-02-08 Fred g52 21
9 2014-02-09 Fred g52 18
10 2014-02-07 Steve e12 17
11 2014-02-08 Steve e12 17
12 2014-02-09 Steve e12 18
13 2014-02-03 Steve g52 52
14 2014-02-04 Steve g52 52
15 2014-02-05 Steve g52 52
16 2014-02-06 Steve g52 25
17 2014-02-07 Steve g52 25
18 2014-02-08 Steve g52 31
19 2014-02-09 Steve g52 40
</code></pre>