如何从字典列表中访问嵌套字典

Question

我有一个字典列表（抱歉有点复杂，但我正在尝试显示真实数据）：

[{'alerts': [{'city': ' city name1',
              'country': 'ZZ',
              'location': {'x': 1, 'y': 3},
              'milis': 1582337463000},
             {'city': ' city name2',
              'country': 'ZZ',
              'location': {'x': 1, 'y': 3},
              'pubMillis': 1582337573000,
              'type': 'TYPE2'}],
  'end': '11:02:00:000',
  'start': '11:01:00:000'},
 {'alerts': [{'city': ' city name3',
              'country': 'ZZ',
              'location': {'x': 1, 'y': 3},
              'milis': 1582337463000}],
  'end': '11:02:00:000',
  'start': '11:01:00:000'}]

一般来说，列表结构是这样的：

[
{ [
    { {},
    },
    { {},
    }
  ],
},
{ [
    { {},
    },
    { {},
    }
  ],
}
]

如果我想访问 city name1，我可以使用这行代码访问：alerts[0]['alerts'][0]['city'].

如果我想访问 city name2，我可以使用此代码访问：alerts[0]['alerts'][1]['city']。

如何循环访问它？

Answer 1

使用嵌套循环：

其中 alerts 等于字典列表

for x in alerts:
    for alert in x['alerts']:
        print(alert['city'])

Answer 2

目标是什么？要获取所有城市名称？

>>> for top_level_alert in alerts:
        for nested_alert in top_level_alert['alerts']:
            print(nested_alert['city'])
city name1
city name2
city name3

Answer 3

使用pandas

data 等于您的字典示例列表

import pandas as pd

# create the dataframe and explode the list of dicts
df = pd.DataFrame(data).explode('alerts').reset_index(drop=True)

# json_normalize the dicts and join back to df
df = df.join(pd.json_normalize(df.alerts))

# drop the alerts column as it's no longer needed
df.drop(columns=['alerts'], inplace=True)

# output
          start           end country         city         milis  location.x  location.y   type     pubMillis
0  11:01:00:000  11:02:00:000      ZZ   city name1  1.582337e+12           1           3    NaN           NaN
1  11:01:00:000  11:02:00:000      ZZ   city name2           NaN           1           3  TYPE2  1.582338e+12
2  11:01:00:000  11:02:00:000      ZZ   city name3  1.582337e+12           1           3    NaN           NaN

如何从字典列表中访问嵌套字典

How to access nested dictionary from a list of dictionaries

python

dictionary

list

json-normalize

使用pandas