如何将对熊猫数据框进行分组操作后获得的数据结构转换为数据框？

Question

说我有从示例数据集在这里：import pandas as pdraw_data = {'regiment': ['Nighthawks', 'Nighthawks', 'Nighthawks', 'Nighthawks', 'Dragoons', 'Dragoons', 'Dragoons', 'Dragoons', 'Scouts', 'Scouts', 'Scouts', 'Scouts'],         'company': ['1st', '1st', '2nd', '2nd', '1st', '1st', '2nd', '2nd','1st', '1st', '2nd', '2nd'],         'name': ['Miller', 'Jacobson', 'Ali', 'Milner', 'Cooze', 'Jacon', 'Ryaner', 'Sone', 'Sloan', 'Piger', 'Riani', 'Ali'],         'preTestScore': [4, 24, 31, 2, 3, 4, 24, 31, 2, 3, 2, 3],        'postTestScore': [25, 94, 57, 62, 70, 25, 94, 57, 62, 70, 62, 70]}df = pd.DataFrame(raw_data, columns = ['regiment', 'company', 'name', 'preTestScore', 'postTestScore'])df我想做一个regimentvs的箱线图preTestScore。为此，我需要找出这两个变量的相对分布。所以，我regiment按preTestScore以下方式分组：df1 = df['regiment'].groupby(df['preTestScore']).count()df1preTestScore2     33     34     224    231    2Name: regiment, dtype: int64

Answer 1

使用to_frame该系列转换成数据帧，然后绘制之前重置索引：

df1 = df['regiment'].groupby(df['preTestScore']).count().to_frame().reset_index()
sns.boxplot(x='regiment', y='preTestScore', data=df1)