如何使用groupby函数根据相似ID将行转换为列

Question

我有数据是以

arun 21-09-2017

raja 21-08-2016

arun 21-10-2017

raja 21-01-2017

我希望我的输入转换如下

arun 21-09-2017 21-01-2017
raja 21-08-2016 21-01-2017

Answer 1

假设您使用的是pandas dataframe，则可以使用groupby获得所需的输出

data = {'name':['arun','raja','arun','raja'],
       'date':['21-09-2017','21-08-2016','21-10-2017','21-01-2017']
       }

df1 = pd.DataFrame(data)

df1.groupby('name')['date'].apply(list).reset_index()

Out[1]:
   name                      date
0  arun  [21-09-2017, 21-10-2017]
1  raja  [21-08-2016, 21-01-2017]