如何使用python flask和mongoalchemy显示对象数组 [英] How to display an array of objects using python flask and mongoalchemy

问题描述

如何编写一个端点，它将为mongoalchemy返回一个json对象数组

How to write an end point which will return a array of json objects for mongoalchemy

我正在尝试如下所示：

@authenticate_bp.route('/users',methods=['GET'])
def user_list():
    users = [x.serialize for x in TokenBasedAuth.query.all()]
    return jsonify({'usersList': users})

模式如下所示

    class TokenBasedAuth(db.Document):
    username = db.StringField()
    password = db.StringField()
    email = db.StringField()
    firstName = db.StringField()
    lastName = db.StringField()

def serialize(g):
    return {
        "_id" : str(g._id),
        "username" : g.username,
        "firstName" : g.firstName,
        "lastName" : g.lastName,
        "password" : g.password,
        "email" : g.email
    }

并将db i中的数据作为sho wn under

and the data in db i as shown below

{ 
    "_id" : ObjectId("586a0f01558b6728388161be"), 
    "username" : "sam", 
    "firstName" : "sam", 
    "lastName" : "123", 
    "password" : "123", 
    "email" : "email@123"
}

我收到如下所示的错误

AttributeError： TokenBasedAuth对象没有属性 serialize // Werkzeug调试器

AttributeError: 'TokenBasedAuth' object has no attribute 'serialize' // Werkzeug Debugger

按预期工作的替代路由如下所示以下

Alternate route which is working as expected is as shown below

@authenticate_bp.route('/users/list')
def users_listItr():
    try:
        users =  TokenBasedAuth.query.all()
        formatted_users=[]
        for user in users:
            print user
            formatted_users.append({
                'username':user.username,
                'password':user.password,
                'email':user.email,
                'firstName':user.firstName,
                'lastName':user.lastName

            })
        return json.dumps({'users':formatted_users}),
        200,{'Content-Type':'application/json'}

    except Exception,e:
        return jsonify(status='ERROR',message=str(e))

但这不是一个好主意，因为我正在尝试为可能包含数千个结构更复杂的文档的模式构建api，请提出一种解决方法

But this is not a good idea as i am trying built the api for a schema which might contain few thousand documents with much more complex structure please suggest a way to go about it please

请帮助获取对象数组

推荐答案

我认为最简单的方法是在结果集上使用带有函数的生成器，以将结果对象序列化为有效的JSON：

The easiest way in my opinion is to use a generator on the result set with a function to serialize the result object to valid JSON:

def serialize(row):
    return {
        "_id" : str(row._id),
        "username" : row.username,
        "firstName" : row.firstName,
        "lastName" : row.lastName,
        "password" : row.password,
        "email" : row.email
    } 

@authenticate_bp.route('/users',methods=['GET'])
def user_list():
    users = [serialize(x) for x in TokenBasedAuth.query.all()]
    return jsonify({'usersList': users})

有几种方法可以尝试创建自定义JSON编码器：请参阅这篇文章。一般来说，对于Flask，我发现，如果我需要对某些东西进行JSON化，那么我需要坚持使用列表和字典，因为这要简单得多。

There are some ways you can try to create a custom JSON encoder: See this post. Generally speaking I've found, for Flask, if I need to JSONify something I need to stick to lists and dicts as it is much simpler.

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