熊猫:使用其他行中的信息填充缺少的日期

假设我有以下熊猫数据框:

Date    Region  Country Cases   Deaths  Lat Long
2020-03-08  Northern Territory  Australia   27  49  -12.4634    130.8456
2020-03-09  Northern Territory  Australia   80  85  -12.4634    130.8456
2020-03-12  Northern Territory  Australia   35  73  -12.4634    130.8456
2020-03-08  Western Australia   Australia   48  20  -31.9505    115.8605
2020-03-09  Western Australia   Australia   70  12  -31.9505    115.8605
2020-03-10  Western Australia   Australia   66  95  -31.9505    115.8605
2020-03-11  Western Australia   Australia   31  38  -31.9505    115.8605
2020-03-12  Western Australia   Australia   40  83  -31.9505    115.8605

我需要更新缺少北领地2020-3-10和2020-3-11的数据框。但是,我想使用除案件和死亡之外的所有信息。像这样:

Date    Region  Country Cases   Deaths  Lat Long
2020-03-08  Northern Territory  Australia   27  49  -12.4634    130.8456
2020-03-09  Northern Territory  Australia   80  85  -12.4634    130.8456
2020-03-10  Northern Territory  Australia   0   0   -12.4634    130.8456
2020-03-11  Northern Territory  Australia   0   0   -12.4634    130.8456
2020-03-12  Northern Territory  Australia   35  73  -12.4634    130.8456
2020-03-08  Western Australia   Australia   48  20  -31.9505    115.8605
2020-03-09  Western Australia   Australia   70  12  -31.9505    115.8605
2020-03-10  Western Australia   Australia   66  95  -31.9505    115.8605
2020-03-11  Western Australia   Australia   31  38  -31.9505    115.8605
2020-03-12  Western Australia   Australia   40  83  -31.9505    115.8605

我能想到的唯一方法是遍历日期和国家/地区的所有组合。

dates = my_df['Date'].unique()
countries = my_df['Country']
regions = my_df['Region']

##yuck
for d in dates:
   for r in regions:
     for c in countries:
       if my_df[(my_df['country']== c) & (my_df['Date']==d) & (my_df['region']==c)].empty:
          my_df.append({'Date':'d, 'Country':c,'Region':r,'cases':0,'deaths':0},ignore_index=True)