import jsond = {'a': 'aaa', 'b': ['b1', 'b2', 'b3'], 'c': 100}json_str = json.dumps(d)print json_str

import jsonclass Customer:  def __init__(self, name, grade, age, home, office):    self.name = name    self.grade = grade    self.age = age    self.address = Address(home, office)  def __repr__(self):    return repr((self.name, self.grade, self.age, self.address.home, self.address.office))class Address:  def __init__(self, home, office):    self.home = home    self.office = office  def __repr__(self):    return repr((self.name, self.grade, self.age))customers = [    Customer('john', 'A', 15, '111', 'aaa'),    Customer('jane', 'B', 12, '222', 'bbb'),    Customer('dave', 'B', 10, '333', 'ccc'),    ]json_str = json.dumps(customers, default=lambda o: o.__dict__, sort_keys=True, indent=4)print json_str

[  {    "address": {      "home": "111",      "office": "aaa"    },    "age": 15,    "grade": "A",    "name": "john"  },  {    "address": {      "home": "222",      "office": "bbb"    },    "age": 12,    "grade": "B",    "name": "jane"  },  {    "address": {      "home": "333",      "office": "ccc"    },    "age": 10,    "grade": "B",    "name": "dave"  }]