Python 如何计算pandas中的分类timeseries数据

这周我决定潜入一点熊猫。我有一个包含历史IRC日志的pandas数据框架，如下所示：

timestamp           action   nick        message
2005-11-04 01:44:33 False    hack-cclub  lex, hey!
2005-11-04 01:44:43 False    hack-cclub  lol, yea thats broke
2005-11-04 01:44:56 False    lex         Slashdot - Updated 2005-11-04 00:23:00 | Micro...
2005-11-04 01:44:56 False    hack-cclub  lex slashdot
2005-11-04 01:45:12 False    lex         port 666 is doom - doom Id Software (or mdqs o..
2005-11-04 01:45:12 False    hack-cclub  lex, port 666
2005-11-04 01:45:21 False    hitokiri    lex, port 23485
2005-11-04 01:45:45 False    hitokiri    lex, port 1024
2005-11-04 01:45:46 True     hack-cclub  slaps lex around with a wet fish

df['nick'].value_counts()[:25]

hack-cclub lex hitokiri
1          0   0
2          0   0
2          1   0
3          1   0
3          2   0
4          2   0
4          2   1
4          2   2
5          2   2

hack-cclub lex hitokiri
1          2   2
1          2   2
1          2   3
1          2   3
1          2   3
1          2   3
1          2   3
1          2   2
1          2   2

大约有550万行，我正在尝试做一些基本的可视化，比如排名前25位之类的。我知道我可以得到像这样的前25个刻痕：

timestamp           action   nick        message
2005-11-04 01:44:33 False    hack-cclub  lex, hey!
2005-11-04 01:44:43 False    hack-cclub  lol, yea thats broke
2005-11-04 01:44:56 False    lex         Slashdot - Updated 2005-11-04 00:23:00 | Micro...
2005-11-04 01:44:56 False    hack-cclub  lex slashdot
2005-11-04 01:45:12 False    lex         port 666 is doom - doom Id Software (or mdqs o..
2005-11-04 01:45:12 False    hack-cclub  lex, port 666
2005-11-04 01:45:21 False    hitokiri    lex, port 23485
2005-11-04 01:45:45 False    hitokiri    lex, port 1024
2005-11-04 01:45:46 True     hack-cclub  slaps lex around with a wet fish

df['nick'].value_counts()[:25]

hack-cclub lex hitokiri
1          0   0
2          0   0
2          1   0
3          1   0
3          2   0
4          2   0
4          2   1
4          2   2
5          2   2

hack-cclub lex hitokiri
1          2   2
1          2   2
1          2   3
1          2   3
1          2   3
1          2   3
1          2   3
1          2   2
1          2   2

我想要的是这样的滚动计数：

timestamp           action   nick        message
2005-11-04 01:44:33 False    hack-cclub  lex, hey!
2005-11-04 01:44:43 False    hack-cclub  lol, yea thats broke
2005-11-04 01:44:56 False    lex         Slashdot - Updated 2005-11-04 00:23:00 | Micro...
2005-11-04 01:44:56 False    hack-cclub  lex slashdot
2005-11-04 01:45:12 False    lex         port 666 is doom - doom Id Software (or mdqs o..
2005-11-04 01:45:12 False    hack-cclub  lex, port 666
2005-11-04 01:45:21 False    hitokiri    lex, port 23485
2005-11-04 01:45:45 False    hitokiri    lex, port 1024
2005-11-04 01:45:46 True     hack-cclub  slaps lex around with a wet fish

df['nick'].value_counts()[:25]

hack-cclub lex hitokiri
1          0   0
2          0   0
2          1   0
3          1   0
3          2   0
4          2   0
4          2   1
4          2   2
5          2   2

hack-cclub lex hitokiri
1          2   2
1          2   2
1          2   3
1          2   3
1          2   3
1          2   3
1          2   3
1          2   2
1          2   2

因此，我可以绘制一个从时间开始的前25个缺口的信息面积图。我知道我可以通过迭代整个数据帧并保持计数来做到这一点，但因为这样做的全部目的是学习使用熊猫，我希望有一种更惯用的方法来做到这一点。拥有相同的数据也很好，但是使用排名，而不是像这样运行计数：

timestamp           action   nick        message
2005-11-04 01:44:33 False    hack-cclub  lex, hey!
2005-11-04 01:44:43 False    hack-cclub  lol, yea thats broke
2005-11-04 01:44:56 False    lex         Slashdot - Updated 2005-11-04 00:23:00 | Micro...
2005-11-04 01:44:56 False    hack-cclub  lex slashdot
2005-11-04 01:45:12 False    lex         port 666 is doom - doom Id Software (or mdqs o..
2005-11-04 01:45:12 False    hack-cclub  lex, port 666
2005-11-04 01:45:21 False    hitokiri    lex, port 23485
2005-11-04 01:45:45 False    hitokiri    lex, port 1024
2005-11-04 01:45:46 True     hack-cclub  slaps lex around with a wet fish

df['nick'].value_counts()[:25]

hack-cclub lex hitokiri
1          0   0
2          0   0
2          1   0
3          1   0
3          2   0
4          2   0
4          2   1
4          2   2
5          2   2

hack-cclub lex hitokiri
1          2   2
1          2   2
1          2   3
1          2   3
1          2   3
1          2   3
1          2   3
1          2   2
1          2   2

IIUC您需要并且：

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我不明白最后一列数据帧。你能解释一下吗？