1. Dataframe分组用groupby("列名")或者groupby(["列名1","列名2"])

import pandas as pd
df = pd.DataFrame({'性别' : ['男', '女', '男', '女',
                            '男', '女', '男', '男'],
                   '成绩' : ['优秀', '优秀', '及格', '差',
                            '及格', '及格', '优秀', '差'],
                   '年龄' : [15,14,15,12,13,14,15,16]})
df

count=df.groupby(["性别","年龄"]).count()
count

count=df.groupby("性别").count()
count

 

 2. Series分组用groupby(Series)

import pandas as pd
ds = pd.Series({'小明' : '男', '小张' : '女', '小赵' : '男'})
GroupBy=ds.groupby(ds)
GroupBy.describe()