Python 将排序应用于 Pandas groupby 操作
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apply sort to a pandas groupby operation
提问by user308827
How do I apply sort to a pandas groupby operation? The command below returns an error saying that 'bool' object is not callable
如何将排序应用于 Pandas groupby 操作？下面的命令返回一个错误，指出“bool”对象不可调用
import pandas as pd
df.groupby('cokey').sort('A')
cokey A B
11168155 18 56
11168155 0 18
11168155 56 96
11168156 96 152
11168156 0 96
采纳答案by EdChum
Normally the sort is performed on the groupby keys and as you've found out you can't call sorton a groupby object, what you could do is call applyand pass the DataFrame.sortfunction and pass the column as the kwarg param:
通常排序是在 groupby 键上执行的，正如您发现不能调用sortgroupby 对象一样，您可以做的是调用apply并传递DataFrame.sort函数并将列作为 kwarg 参数传递：
In [58]:
df.groupby('cokey').apply(pd.DataFrame.sort, 'A')
Out[58]:
cokey A B
cokey
11168155 1 11168155 0 18
0 11168155 18 56
2 11168155 56 96
3 11168155 96 152
Alternatively you could just sort the df prior to grouping:
或者，您可以在分组之前对 df 进行排序：
df.sort('A').groupby('cokey')
Update
更新
For version 0.17.0and above DataFrame.sortis now deprecated see the docs, one should now use DataFrame.sort_values:
对于现在已弃用的版本0.17.0及更高版本，DataFrame.sort请参阅文档，现在应该使用DataFrame.sort_values：
df.groupby('cokey').apply(pd.DataFrame.sort_values, 'A')
Adding @xgdgsc 's answer in comments to here; in case you need to set ascending flag.
在此处的评论中添加 @xgdgsc 的答案；如果您需要设置升序标志。
df.groupby('cokey').apply(pd.DataFrame.sort_values, 'A', ascending=False)
