JSON dump for User defined class in python -

here how want data : (key=name, value=[dob,[misc1, misc2,..]])

    # sample code inputnames = [ ('james', ['1990-01-19', ['james1', 'james2', 'james3'] ]), ('julie', ['1991-08-07', ['julie1', 'julie2'] ]), ('mikey', ['1989-01-23', ['mikey1'] ]), ('sarah', ['1988-02-05', ['sarah1', 'sarah2', 'sarah3', 'sarah4'] ]) ] class empdata (list):     def __init__ (self, misc=none):             list.__init__([])             # print('add empdata: ',misc[0],misc[1])             self.dob = misc[0]             self.extend(misc[1])     def edprint(self):             return(self.dob, self) class myemp():     def __init__ (self, anm, amisc=none):             self.nm = anm             self.details = empdata(amisc)     def printme(self):             print(self.nm, self.details.edprint())  emps={} in inputnames:     m = myemp(i[0],i[1])     emps[m] = m print(emps)  # prints addresses of variables  # actual data use following lines ea in emps:         emps[ea].printme()   try:        open('data.json','w') wfd:              json.dump(emps, wfd)               except ioerror ioerr:             print('file error: ',str(ioerr)) wfd.close() 

the above gives me error: typeerror: key <main.myemp object @ 0x10143d588> not string unable figure out how dump dict of myemp data structures json

before can dump json need explicitly convert data serializable type dict or list. using list comprehension:

>>> d = [{'key':ea.nm, 'value':[ea.details.dob, ea.details]} ea in emps] >>> json.dumps(d) '[{"value": ["1991-08-07", ["julie1", "julie2"]], "key": "julie"}, {"value": ["1989-01-23", ["mikey1"]], "key": "mikey"}, {"value": ["1990-01-19", ["james1", "james2", "james3"]], "key": "james"}, {"value": ["1988-02-05", ["sarah1", "sarah2", "sarah3", "sarah4"]], "key": "sarah"}]'