为什么使用Python读取JSON文件时，搜索指定关键字Python会报KeyError的错，但JSON文件中确实有对应的关键词？

Question

使用Python读取JSON文件时，搜索指定关键字‘center’Python会报KeyError的错，但JSON文件中确实有‘center’关键词。

这是Python的代码

import json

# 探索数据的结构
filename = 'data/中华人民共和国.json'
with open(filename,encoding='utf-8') as f:
    all_eq_data = json.load(f)

# 以易读的方式存储
# readable_file = 'data/1中华人民共和国.json'
# with open(readable_file, 'w', encoding='utf-8') as f:
#     json.dump(all_eq_data, f, indent=4)# 接受一个JSON数据对象和一个文件对象，并将数据写入这个文件中，indent=4让数据结构匹配缩进量来设置数据的格式

# 提取地区的数量
all_eq_dicts = all_eq_data['features']

# 提取邮政编码和位置信息
adcodes, names, lons, lats = [], [], [], []
for eq_dict in all_eq_dicts:
    adcode = eq_dict['properties']['adcode']
    name = eq_dict['properties']['name']
    lon = eq_dict['properties']['center'][0]
    lat = eq_dict['properties']['center'][1]
    adcodes.append(adcode)
    names.append(name)
    lons.append(lon)
    lats.append(lat)



print(adcodes)
print(names)
print(lons)
print(lats)

这是对应的JSON文件，只截取了一部分

{
    "type": "FeatureCollection",
    "features": [
        {
            "type": "Feature",
            "properties": {
                "adcode": 110000,
                "name": "\u5317\u4eac\u5e02",
                "center": [
                    116.405285,
                    39.904989
                ],
                "centroid": [
                    116.41995,
                    40.18994
                ],
                "childrenNum": 16,
                "level": "province",
                "parent": {
                    "adcode": 100000
                },
                "subFeatureIndex": 0,
                "acroutes": [
                    100000
                ]
            }
      }
}

这是报的错

Traceback (most recent call last):
  File "D:\Python\Py project\py_Learn\JSON\1eq_explore.py", line 21, in <module>
    lon = eq_dict['properties']['center'][0]
KeyError: 'center'

希望有方法可以正常读取到数据

Answer 1

读取成字典后这样取值：

dic={
    "type": "FeatureCollection",
    "features": [
        {
            "type": "Feature",
            "properties": {
                "adcode": 110000,
                "name": "\u5317\u4eac\u5e02",
                "center": [
                    116.405285,
                    39.904989
                ],
                "centroid": [
                    116.41995,
                    40.18994
                ],
                "childrenNum": 16,
                "level": "province",
                "parent": {
                    "adcode": 100000
                },
                "subFeatureIndex": 0,
                "acroutes": [
                    100000
                ]
            }
    }],
}
for i in range(len(dic['features'])):
    print(dic['features'][i]['properties']['center'][0])

结果：

F:\2021\qa\ot3>t4
116.405285

如有帮助，请点采纳。