需要帮助从多个列计算唯一值吗

Question

我有一个带有两个字段的pd数据帧：DBA Name（设备名称）和License。DBA名称有多个列表，其中一些具有相同的许可证，而另一些则没有。你知道吗

我想找出所有DBA名称的实例有多少。我还想知道他们每个人有多少独特的许可证。你知道吗

我尝试使用value_counts（），但这只适用于数据框中的一个字段。我也尝试过使用apply（），但没有成功。你知道吗

我在下面展示了示例代码。请告诉我你的想法。你知道吗

data = data[['DBA Name','License #']]

data:
        DBA Name                    License #
1   BUSY BUMBLE BEE ACADEMY DAYCARE 2215472.0
2   BUSY BUMBLE BEE ACADEMY DAYCARE 3793.0
3   BUSY BUMBLE BEE ACADEMY DAYCARE 2215472.0
4   BUSY BUMBLE BEE ACADEMY DAYCARE 1194190.0
5   BUSY BUMBLE BEE ACADEMY DAYCARE 2215472.0
6   BUSY BUMBLE BEE ACADEMY DAYCARE 1194190.0
7   BUSY BUMBLE BEE ACADEMY DAYCARE 1194190.0
8   BUSY BUMBLE BEE ACADEMY DAYCARE 3793.0
9   BUSY BUMBLE BEE ACADEMY DAYCARE 3793.0
10  BOTTLES TO BOOKS LEARNING CENTER 1943545.0
11  BOTTLES TO BOOKS LEARNING CENTER 1943545.0
12  BOTTLES TO BOOKS LEARNING CENTER 1926534.0
13  BOTTLES TO BOOKS LEARNING CENTER    1926534.0
14  BOTTLES TO BOOKS LEARNING CENTER    1926534.0
15  BOTTLES TO BOOKS LEARNING CENTER    1943545.0
16  BOTTLES TO BOOKS LEARNING CENTER    1926534.0
17  BOTTLES TO BOOKS LEARNING CENTER    1943545.0
18  A CHILD'S WORLD EARLY LEARNING CENTER   1357825.0
19  A CHILD'S WORLD EARLY LEARNING CENTER   1357825.0
20  A CHILD'S WORLD EARLY LEARNING CENTER   1768092.0
21  A CHILD'S WORLD EARLY LEARNING CENTER   1768092.0
22  A CHILD'S WORLD EARLY LEARNING CENTER   1357825.0
23  A CHILD'S WORLD EARLY LEARNING CENTER   1768092.0
24  A CHILD'S WORLD EARLY LEARNING CENTER   1357825.0

Answer 1

将pd.DataFrame.groupby与nunique和agg一起使用：

import pandas as pd

df.groupby('DBA Name').agg({'DBA Name': 'count', 'License #': 'nunique'})

输出：

                                       DBA Name  License #
DBA Name                                                  
A CHILD'S WORLD EARLY LEARNING CENTER         7          2
BOTTLES TO BOOKS LEARNING CENTER              8          2
BUSY BUMBLE BEE ACADEMY DAYCARE               9          3