通常在 Pandas 中将长格式的数据框转换为宽格式时,我们会使用 pivot、pivot_table、unstack 或 groupby,但是这些方法仅适用于可聚合的元素。如果要以相同的方式转换分类数据框呢?
例如:
例如:
d = {'Fruit':['Apple', 'Apple', 'Apple', 'Kiwi'],
'Color1':['Red', 'Yellow', 'Red', 'Green'],
'Color2':['Red', 'Red', 'Green', 'Brown'],'Color3':[np.nan,np.nan,'Red',np.nan]}
pd.DataFrame(d)
Fruit Color1 Color2 Color3
0 Apple Red Red NaN
1 Apple Yellow Red NaN
2 Apple Red Green Red
3 Kiwi Green Brown NaN
应该变成以下内容:
d = {'Fruit':['Apple','Kiwi'],
'Color1':['Red','Green'],
'Color1_1':['Yellow',np.nan],
'Color1_2':['Red',np.nan],
'Color2':['Red', 'Brown'],
'Color2_1':['Red',np.nan],
'Color2_2':['Green',np.nan],
'Color3':[np.nan,np.nan],
'Color3_1':[np.nan,np.nan],
'Color3_2':['Red',np.nan]
}
pd.DataFrame(d)
Fruit Color1 Color1_1 Color1_2 Color2 Color2_1 Color2_2 Color3 Color3_1 Color3_2
0 Apple Red Yellow Red Red Red Green NaN NaN Red
1 Kiwi Green NaN NaN Brown NaN NaN NaN NaN NaN