Question

编辑：更新的代码，不再提出指定的错误

我正在尝试将以下内容编码为json格式：

class Map:
    """
    Storage for cities and routes
    """

    def __init__(self):
        self.cities = {}
        self.routes = {}

班级路线： “”” 存储路线信息 “”“

def __init__(self, src, dest, dist):
    self.flight_path = src + '-' + dest
    self.src = src
    self.dest = dest
    self.dist = dist

def to_json(self):
    return {'source': self.src, 'destination': self.dest, 
    'distance': self.dist}

班级城市： “”” 存储城市信息 “”“

def __init__(self, code, name, country, continent, 
             timezone, coordinates, population, region):
    self.code = code
    self.name = name
    self.country = country
    self.continent = continent
    self.timezone = timezone
    self.coordinates = coordinates
    self.population = population
    self.region = region

def to_json(self):
    return {'code': self.code, 'name': self.name, 'country': self.country, 
    'continent': self.continent, 'timezone':  self.timezone, 
    'coordinates': self.coordinates, 'population': self.population, 
    'region': self.region}

我希望python的“cities”部分编码存储在map.cities中的所有城市信息，以及编码存储在map.routes中的所有路径信息的“routes”部分

我的尝试：

def map_to_json(my_file, air_map):
    """
    Saves JSON Data
    """
    with open(my_file, 'w') as outfile:
        for entry in air_map.cities:
            json.dumps(air_map.cities[entry].to_json(), outfile)
        for entry in air_map.routes:
            json.dumps(air_map.routes[entry].to_json(), outfile)

    outfile.close()

其中air_map是地图，my_file是文件路径。

我收到以下错误：

>    Jmap.map_to_json('Resources/map_save.json', air_map)   File
> "JSONToMap.py", line 53, in map_to_json
>     json.dumps(air_map.cities, outfile)   File "C:\Python27\lib\json\__init__.py", line 250, in dumps
>     sort_keys=sort_keys, **kw).encode(obj)   File "C:\Python27\lib\json\encoder.py", line 207, in encode
>     chunks = self.iterencode(o, _one_shot=True)   File "C:\Python27\lib\json\encoder.py", line 270, in iterencode
>     return _iterencode(o, 0)   File "C:\Python27\lib\json\encoder.py", line 184, in default
>     raise TypeError(repr(o) + " is not JSON serializable") TypeError: <City.City instance at 0x0417FC88> is not JSON serializable
> >>>

我对python和JSON都很陌生，所以请帮助。

由于

Answer 1

您无法直接序列化对象。试试这个：

class City:
    """
    Stores city info
    """

    def __init__(self, code, name, country, continent, 
                 timezone, coordinates, population, region):
        self.code = code
        self.name = name
        self.country = country
        self.continent = continent
        self.timezone = timezone
        self.coordinates = coordinates
        self.population = population
        self.region = region

    def to_json(self):
        return {'code': self.code, 'name': self.name,
                'country': self.country, 
                #rest of the attributes...
               }

并且在打电话时，

json.dumps(air_map.cities.to_json(), outfile)

同样适用于Routes模型。

如果您正在处理对象列表，您可以随时执行：

json.dumps([city.to_json() for city in air_map.cities], outfile)

如果air_map.cities是城市列表

python中的字典到JSON

1 个答案: