Python 如何从dataframe中获取唯一的行,同时在某些列中保留最大值的行?

Python 如何从dataframe中获取唯一的行,同时在某些列中保留最大值的行?,python,pandas,Python,Pandas,我有一个数据帧(来自以下csv): 我想删除timestamp列上的重复项,同时保留'load'值最大的行 在这种情况下: load,timestamp,timestr 0,1576147339.49,124219 0,1576147339.502,124219 2,1576147339.637,124219 1,1576147339.641,124219 9,1576147339.662,124219 8,1576147339.663,124219 0,1576147339.673,12421

我有一个数据帧(来自以下csv):

我想删除timestamp列上的重复项,同时保留'load'值最大的行

在这种情况下:

load,timestamp,timestr
0,1576147339.49,124219
0,1576147339.502,124219
2,1576147339.637,124219
1,1576147339.641,124219
9,1576147339.662,124219
8,1576147339.663,124219
0,1576147339.673,124219
3,1576147341.567,124221
2,1576147341.568,124221
1,1576147341.569,124221
0,1576147341.57,124221
4,1576147341.581,124221
“加载”的最大值不必首先出现


最好的方法是什么?

尝试使用
groupby

print(df.groupby('timestamp', as_index=False)['load'].max().join(df['timestr']))
输出:

       timestamp  load  timestr
0   1.576147e+09     0   124219
1   1.576147e+09     0   124219
2   1.576147e+09     2   124219
3   1.576147e+09     1   124219
4   1.576147e+09     9   124219
5   1.576147e+09     8   124219
6   1.576147e+09     0   124219
7   1.576147e+09     3   124221
8   1.576147e+09     2   124221
9   1.576147e+09     1   124221
10  1.576147e+09     0   124221
11  1.576147e+09     4   124221

重置精度并使用groupby显示最大值:

pd.options.display.float_format = '{:.3f}'.format 
df.groupby('timestamp').max()
输出:

                load  timestr
timestamp                    
1576147339.490     0   124219
1576147339.502     0   124219
1576147339.637     2   124219
1576147339.641     1   124219
1576147339.662     9   124219
1576147339.663     8   124219
1576147339.673     0   124219
1576147341.567     3   124221
1576147341.568     2   124221
1576147341.569     1   124221
1576147341.570     0   124221
1576147341.581     4   124221

groupby()+max()?我对熊猫还不熟悉,我想可以,但是怎么会呢?我接受得太快了。。。我想在载荷柱上找到最大值。我该怎么写?
                load  timestr
timestamp                    
1576147339.490     0   124219
1576147339.502     0   124219
1576147339.637     2   124219
1576147339.641     1   124219
1576147339.662     9   124219
1576147339.663     8   124219
1576147339.673     0   124219
1576147341.567     3   124221
1576147341.568     2   124221
1576147341.569     1   124221
1576147341.570     0   124221
1576147341.581     4   124221