错误：TypeError：ColumnClause类型的对象不是JSON可序列化的Python3

问题描述

嗨，我收到此错误。 TypeError：ColumnClause类型的对象不可JSON序列化。

整件事：

    [2020-10-26 22:17:58,448] ERROR in app: Exception on /all-user [GET]
Traceback (most recent call last):
  File "c:\users\ryand\.virtualenvs\main-api-ucgvpon1\lib\site-packages\flask\app.py",line 2447,in wsgi_app
    response = self.full_dispatch_request()
  File "c:\users\ryand\.virtualenvs\main-api-ucgvpon1\lib\site-packages\flask\app.py",line 1952,in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "c:\users\ryand\.virtualenvs\main-api-ucgvpon1\lib\site-packages\flask\app.py",line 1821,in handle_user_exception
    reraise(exc_type,exc_value,tb)
  File "c:\users\ryand\.virtualenvs\main-api-ucgvpon1\lib\site-packages\flask\_compat.py",line 39,in reraise
    raise value
  File "c:\users\ryand\.virtualenvs\main-api-ucgvpon1\lib\site-packages\flask\app.py",line 1950,in full_dispatch_request
    rv = self.dispatch_request()
  File "c:\users\ryand\.virtualenvs\main-api-ucgvpon1\lib\site-packages\flask\app.py",line 1936,in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "C:\Users\ryand\Desktop\mealplansfree\main-api\api.py",line 36,in decorated
    return f(*args,**kwargs)
  File "C:\Users\ryand\Desktop\mealplansfree\main-api\api.py",line 59,in get_all_users
    return jsonify({'users' : output})
  File "c:\users\ryand\.virtualenvs\main-api-ucgvpon1\lib\site-packages\flask\json\__init__.py",line 370,in jsonify
    dumps(data,indent=indent,separators=separators) + "\n",File "c:\users\ryand\.virtualenvs\main-api-ucgvpon1\lib\site-packages\flask\json\__init__.py",line 211,in dumps
    rv = _json.dumps(obj,**kwargs)
  File "c:\users\ryand\appdata\local\programs\python\python38-32\lib\json\__init__.py",line 234,in dumps
    return cls(
  File "c:\users\ryand\appdata\local\programs\python\python38-32\lib\json\encoder.py",line 199,in encode
    chunks = self.iterencode(o,_one_shot=True)
  File "c:\users\ryand\appdata\local\programs\python\python38-32\lib\json\encoder.py",line 257,in iterencode
    return _iterencode(o,0)
  File "c:\users\ryand\.virtualenvs\main-api-ucgvpon1\lib\site-packages\flask\json\__init__.py",line 100,in default
    return _json.JSONEncoder.default(self,o)
  File "c:\users\ryand\appdata\local\programs\python\python38-32\lib\json\encoder.py",line 179,in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type ColumnClause is not JSON serializable

这是上面的代码。

  @app.route('/all-user',methods=['GET'])
@application_required
def get_all_users():

    users = User.query.all()

    output = []

    for user in users:
        user_data = {}
        user_data['user_id'] = user.user_id
        user_data['full_name'] = user.full_name
        user_data['username'] = user.username
        user_data['password'] = user.password
        user_data['admin'] = user.admin
        output.append(user_data)

    return jsonify({'users' : output})

这是密钥检查

def application_required(f):
    @wraps(f)
    def decorated(*args,**kwargs):
        token = None

        if 'x-access-key' in request.headers:
            token = request.headers['x-access-key']

        if not token:
            return jsonify({'message' : 'ERROR x-access-key missing or incorrect.'}),401

        if token == app.config['SECRET_KEY']:
            return f(*args,**kwargs)
        else:
            return jsonify({'message' : 'ERROR x-access-key missing or incorrect.'}),401

    return decorated

如果有人知道发生了什么，或者可以指导我完成所发生的事情以及如何调试这些事情，那就太好了！

解决方法

我在这里找到了答案：SQLAlchemy warning: column won't be part of the declarative mapping

我在用户模型中的用户名中忽略了它是小写的c而不是大写的C。这可以修复错误，现在可以正常工作了。谢谢！

原因可能是数据类型。您正在使用很多数据类型。尝试减少数据类型更改。

flask jsonify python