pandas 简单的旋转
示例
首先尝试使用pivot：
import pandas as pd
import numpy as np
df = pd.DataFrame({'Name':['Mary', 'Josh','Jon','Lucy', 'Jane', 'Sue'],
'Age':[34, 37, 29, 40, 29, 31],
'City':['Boston','New York', 'Chicago', 'Los Angeles', 'Chicago', 'Boston'],
'Position':['Manager','Programmer','Manager','Manager','Programmer', 'Programmer']},
columns=['Name','Position','City','Age'])
print (df)
Name Position City Age
0 Mary Manager Boston 34
1 Josh Programmer New York 37
2 Jon Manager Chicago 29
3 Lucy Manager Los Angeles 40
4 Jane Programmer Chicago 29
5 Sue Programmer Boston 31
print (df.pivot(index='Position', columns='City', values='Age'))
City Boston Chicago Los Angeles New York
Position
Manager 34.0 29.0 40.0 NaN
Programmer 31.0 29.0 NaN 37.0如果需要重置索引，请删除列名称并填写NaN值：
#pivoting by numbers - column Age
print (df.pivot(index='Position', columns='City', values='Age')
.reset_index()
.rename_axis(None, axis=1)
.fillna(0))
Position Boston Chicago Los Angeles New York
0 Manager 34.0 29.0 40.0 0.0
1 Programmer 31.0 29.0 0.0 37.0
#pivoting by strings - column Name
print (df.pivot(index='Position', columns='City', values='Name'))
City Boston Chicago Los Angeles New York
Position
Manager Mary Jon Lucy None
Programmer Sue Jane None Josh