Writing an object's attributes to a sqlite3 database

Question

In my application I have a class User and the class has id, ip, os as attributes or values - not sure which one is the correct term.

I fetch the data needed and write it to a dictionary through json.loads(), for example:

data = {'id': '111', 'ip': '127.0.0.1', 'os': 'windows'}

I use the data to create a new User i.e.

user1 = User(111, "127.0.0.", "windows")

I have a database with a table user that stores the same attributes/values and I want to store that user in the database.

So is there a way to store the user in the databse without getting the data from the dictionary again?

Answer 1

扩展@ junnytony的答案，你可以从字典中检索对象，使用简单的方法将对象设为字典。

示例：

class User(object):
    def __init__(self, id=None, ip=None, os=None, input_dict=None):
        if input_dict:
            self.from_dict(input_dict)
        else:
            self.id = id
            self.ip = ip
            self.os = os

    def from_dict(self, input_dict):
        self.id = input_dict.get('id')
        self.ip = input_dict.get('ip')
        self.os = input_dict.get('os')

    def to_dict(self):
        return {'id': self.id, 'ip': self.ip, 'os': self.os}

    def __repr__(self):
        return "id: {0}, ip: {1}, os: {2}".format(self.id, self.ip, self.os)

user1 = User(1, "127.0.0.1", "windows")
dict1 = user1.to_dict()
dict1['id'] = 2
user2 = User(input_dict=dict1)

print user1
# id: 1, ip: 127.0.0.1, os: windows

print user2
# id: 2, ip: 127.0.0.1, os: windows

Answer 2

Why would you need to get the data from the dictionary again? If you want to store your User object why not just write a function that accesses User.id, User.ip and User.os and passes it to the Sqlite interface?

If that solution doesn't work for you: you can create a method in your User object that converts the objects attributes to a dictionary...something like User.to_dict(). There is already the inbuilt __dict__ attribute of every object but the issue with using that directly is that it may contain other parameters that you don't want to push to the database layer.

Example:

Class User(object):
    def __init__(id, ip, os):
        self.id = id
        self.ip = ip
        self.os = os

    def to_dict():
        return {'id': self.id, 'ip': self.ip, 'os': self.os}