how to convert a list of object to json format in python

Question

I have a class in python. And I made a list that contains this class instances. I want to convert this list to json. Here is my class

class IpPort:
    def __init__(self,ip,port,time,status):
        self.ip=ip
        self.port=port
        self.time=time
        self.status=status

And I have a list of this object. I want to convert this list to json format to send a socket. But I could not. How can I do this? I want it to be like:

{"IpPortList":{[]}}

EDIT Here is my code for this.But it did not work:

li=list()

i1=IpPort("kk",12,None,"w")
i2=IpPort("kk",15,None,"s")

li.append(i1)
li.append(i2)

jsons= json.dumps(li)


s.send(jsons)

And i want to send this json to a socket.After that i want to take the json at the other side.In the other side again i want to convert it to list.

Solution

You should code a dump method in your object and use it when sending things to json module:

class IpPort:
    def __init__(self, ip, port, time, status):
        self.ip = ip
        self.port = port
        self.time = time
        self.status = status

    def dump(self):
        return {"IpPortList": {'ip': self.ip,
                               'port': self.port,
                               'time': self.time,
                               'status': self.status}}

And when converting data to json:

json.dumps([o.dump() for o in my_list_of_ipport])

You can even make it more automatic by creating a custom encoder for your JSON but it seems like overkill here.

Edit:

To answer the comment on the load part, if you just want a list of dict json.loads is the way to go. If you want a list of IpPort you have to ways to do it, either you do the following (considering that your dumped dicts are flat):

ip_ports = [IpPort(**attrs) for attrs in json.loads(dumped_ipports)]

Note: The ** operator transform a dict into keyword arguments.

If your dumped dicts are not flat (which is your case), you should create a static method load which returns an instance of the object created from a dump:

class IpPort:
    ... blablabla ...

    @staticmethod
    def load(dumped_obj):
        return IpPort(dumped_obj['IpPortList']['ip'],
                      dumped_obj['IpPortList']['port'],
                      dumped_obj['IpPortList']['time'],
                      dumped_obj['IpPortList']['status'])

And the way to make it a list:

my_ip_ports = [IpPort.load(dumped_ipport)
               for dumped_ipport in json.loads(dumped_stuff)]

Comments

[akinKaplanoglu]

Thank You very [email protected] can i take the json object in other side?And i want to convert it to list again .

[Benoît Latinier]

Edited to add load part.