Dataframe 将数据帧中的相等索引合并到新数据帧

嗨，我是蟒蛇和熊猫的新手。我和熊猫做了一些小项目，但现在我被卡住了

从API我得到了一个数据帧

下面是一个代码来演示

import pandas as pd

data = [['2018', 'Production', 10], ['2018', 'Feedin', 15], ['2018', 'Purchased', 14], ['2019', 'Feedin', 5], ['2019', 'Purchased', 4], ['2019', 'Production', 11],['2017', 'Feedin', 130],['2017', 'Production', 0], ['2017', 'Purchased', 20]]
columnnames = ['Date', 'type', 'value']

df = pd.DataFrame(data)
df.columns = columnnames
df = df.set_index('Date')

grouped = df.groupby('Date')

#what to do here?
#for i in grouped:




data = [['2018', 10, 15, 14], ['2019' , 11, 5, 4], [2017, 0, 130, 20]]
columnnames = ['Date', 'Production', 'Feedin', 'Purchased']
good = pd.DataFrame(data, columns=columnnames)
good = good.set_index('Date')

df=我如何获得数据

           type  value
Date                   
2018  Production     10
2018      Feedin     15
2018   Purchased     14
2019      Feedin      5
2019   Purchased      4
2019  Production     11
2017      Feedin    130
2017  Production      0
2017   Purchased     20

     Production  Feedin  Purchased
Date                               
2018          10      15         14
2019          11       5          4
2017           0     130         20

good=我想要的数据是什么

           type  value
Date                   
2018  Production     10
2018      Feedin     15
2018   Purchased     14
2019      Feedin      5
2019   Purchased      4
2019  Production     11
2017      Feedin    130
2017  Production      0
2017   Purchased     20

     Production  Feedin  Purchased
Date                               
2018          10      15         14
2019          11       5          4
2017           0     130         20