Groupby and sort multiple columns' values raising an AttributeError: 'DataFrameGroupBy' object has no attribute 'sort_values'

Question

对于下面的玩具数据集，我正在尝试按 target_name 分组并按多列对值进行排序：valid_mse、valid_r2_score 使用：df.groupby('target_name').sort_values(by=['valid_mse', 'valid_r2_score'], ascending=[True, False])

  target_name  train_mse  valid_mse  train_r2_score  valid_r2_score
0         CPI   1.102079   1.842212        0.947458       -0.624665
1         CPI   1.301734   1.890085        0.928005       -0.777463
2         CPI   0.471222   1.078413        0.990599        0.311849
3         PPI   0.113998   0.135523        0.662532        0.262387
4         PPI   0.095434   0.176431        0.752242       -0.422994
5         PPI   0.097648   0.174544        0.744522       -0.203880

但它引发了一个错误：AttributeError: 'DataFrameGroupBy' object has no attribute 'sort_values'。我还尝试使用 df.groupby('target_name').sort_values(by='valid_mse', ascending=True) 对一列进行排序，它会引发相同的错误。

有谁知道我怎样才能正确解决这个问题？谢谢。

字典格式的数据：

{'target_name': {0: 'CPI', 1: 'CPI', 2: 'CPI', 3: 'PPI', 4: 'PPI', 5: 'PPI'},
 'train_mse': {0: 1.102079409,
  1: 1.301734392,
  2: 0.471221642,
  3: 0.11399796,
  4: 0.09543417,
  5: 0.097647639},
 'valid_mse': {0: 1.842212034,
  1: 1.890085418,
  2: 1.078413107,
  3: 0.135523283,
  4: 0.176431247,
  5: 0.174543796},
 'train_r2_score': {0: 0.947458162,
  1: 0.928005473,
  2: 0.990599137,
  3: 0.662532128,
  4: 0.752241595,
  5: 0.744522334},
 'valid_r2_score': {0: -0.624665246,
  1: -0.777462993,
  2: 0.311849214,
  3: 0.262387135,
  4: -0.422993602,
  5: -0.203880075}}

引用link:

How to sort a dataFrame in python pandas by two or more columns?

Answer 1

groupBy中没有sort_values（groupby创建的对象）

简单的三列排序不就可以得到想要的数据吗？类似于：

df.sort_values(by=['target_name', 'valid_mse', 'valid_r2_score'],
               ascending=[True, True, False])

这将首先按 target_name 列排序，然后按 valid_mse 排序，然后按 valid_r2_score 排序，因此可以说这就是你想要的：

  target_name  train_mse  valid_mse  train_r2_score  valid_r2_score
2         CPI   0.471222   1.078413        0.990599        0.311849
0         CPI   1.102079   1.842212        0.947458       -0.624665
1         CPI   1.301734   1.890085        0.928005       -0.777463
3         PPI   0.113998   0.135523        0.662532        0.262387
5         PPI   0.097648   0.174544        0.744522       -0.203880
4         PPI   0.095434   0.176431        0.752242       -0.422994

Groupby and sort multiple columns' values raising an AttributeError: 'DataFrameGroupBy' object has no attribute 'sort_values'

Groupby and sort multiple columns' values raising an AttributeError: 'DataFrameGroupBy' object has no attribute 'sort_values'

dataframe

python-3.x

pandas

pandas-groupby