python - 缺少必需的位置参数(日期时间)

Question

我是 Flask 和 Postgres 新手...

我正在学习本教程: https://auth0.com/blog/using-python-flask-and-angular-to-build-modern-apps-part-1/

我创建了一个这样的实体:

from marshmallow import Schema, fields
from sqlalchemy import Column, String, Boolean, Date

from .entity import Entity, Base


class Strategy(Entity, Base):
    __tablename__ = 'strategies'

    name = Column(String)
    description = Column(String)
    startDate = Column(Date)
    endDate = Column(Date)
    allowTeamToVote = Column(Boolean)
    votingDeadline = Column(Date)
    isActive = Column(Boolean)

    def __init__(self, name, description, startDate, endDate, allowTeamToVote, votingDeadline, created_by):
        Entity.__init__(self, created_by)
        self.name = name
        self.description = description
        self.startDate = startDate
        self.endDate = endDate
        self.allowTeamToVote = allowTeamToVote
        self.votingDeadline = votingDeadline
        self.isActive = True

class StrategySchema(Schema):
    id = fields.Number()
    name = fields.Str()    
    description = fields.Str()
    startDate = fields.DateTime()
    endDate = fields.DateTime()
    allowTeamToVote = fields.Boolean()
    votingDeadline = fields.DateTime()
    isActive = fields.Boolean()
    created_at = fields.DateTime()
    updated_at = fields.DateTime()
    last_updated_by = fields.Str()

和一个 Post 方法:

@app.route('/strategies', methods=['POST'])
@requires_auth
def add_strategy():
    # mount Strategy object
    print(request.get_json())
    posted_strategy = StrategySchema(only=('name', 'description', 'startDate', 'endDate', 'allowTeamToVote', 'votingDeadline', 'isActive'))\
        .load(request.get_json())
print(posted_strategy.data)


    strategy = Strategy(**posted_strategy.data, created_by="HTTP post request")

    # persist Strategy
    session = Session()
    session.add(strategy)
    session.commit()

    # return created Strategy
    new_strategy = StrategySchema().dump(Strategy).data
    session.close()
    return jsonify(new_strategy), 201

当调用 .load(request.get_json()) 方法时没有得到转换的是所有三个日期时间值。

我收到以下错误:

 __init__() missing 3 required positional arguments: 'startDate', 'endDate', and 'votingDeadline'

我做错了什么？

---

第一个打印语句:

{'objectives': [{'name': 'afasdfdsa'}], 'name': 'sdasdfdsaf', 'description': 'df
asfasdf', 'startDate': '05/31/2018', 'endDate': '05/31/2018', 'allowTeamToVote':
True, 'votingDeadline': '05/31/2018'}

第二个打印语句:

{'allowTeamToVote': True, 'name': 'asfdfsd', 'description': 'dsfasdfs'}

完整异常:

127.0.0.1 - - [16/May/2018 20:43:43] "OPTIONS /strategies HTTP/1.1" 200 - [2018-05-16 20:43:44,712] ERROR in app: Exception on /strategies [POST] Traceback (most recent call last): File "c:\users\jason.virtualenvs\backend-foekiio5\lib\site-packages\flask\app.py", line 1982, in wsgi_app response = self.full_dispatch_request() File "c:\users\jason.virtualenvs\backend-foekiio5\lib\site-packages\flask\app.py", line 1614, in full_dispatch_request rv = self.handle_user_exception(e) File "c:\users\jason.virtualenvs\backend-foekiio5\lib\site-packages\flask_cors\extension.py", line 161, in wrapped_function return cors_after_request(app.make_response(f(*args, **kwargs))) File "c:\users\jason.virtualenvs\backend-foekiio5\lib\site-packages\flask\app.py", line 1517, in handle_user_exception reraise(exc_type, exc_value, tb) File "c:\users\jason.virtualenvs\backend-foekiio5\lib\site-packages\flask_compat.py", line 33, in reraise raise value File "c:\users\jason.virtualenvs\backend-foekiio5\lib\site-packages\flask\app.py", line 1612, in full_dispatch_request rv = self.dispatch_request() File "c:\users\jason.virtualenvs\backend-foekiio5\lib\site-packages\flask\app.py", line 1598, in dispatch_request return self.view_functionsrule.endpoint File "C:\projects\Python Projects\three-back\backend\src\auth.py", line 101, in decorated return f(*args, **kwargs) File "C:\projects\Python Projects\three-back\backend\src\main.py", line 41, in add_strategy strategy = Strategy(**posted_strategy.data, created_by="HTTP post request") TypeError: init() missing 3 required positional arguments: 'startDate', 'endDate', and 'votingDeadline' 127.0.0.1 - - [16/May/2018 20:43:44] "POST /strategies HTTP/1.1" 500 -

Answer 1

What doesn't getting converted when .load(request.get_json()) method is called is all three datetime values.

您的第二个 print 语句在函数之外。所以你得到了错误的输出。

I get the following error:

您正在将字典(键值对)传递给该方法，但它需要位置参数。

将此行更改为:

`strategy = Strategy(*posted_strategy.data.values(), created_by="HTTP post request")`

总的来说，是这样的:

@app.route('/strategies', methods=['POST'])
@requires_auth
def add_strategy():
    # mount Strategy object
    print(request.get_json())
    posted_strategy = StrategySchema(only=('name', 'description', 'startDate', 'endDate', 'allowTeamToVote', 'votingDeadline', 'isActive'))\
        .load(request.get_json())
    print(posted_strategy.data)


    strategy = Strategy(*posted_strategy.data.values(), created_by="HTTP post request")

如 documentation here 中所述，Marshmallow 有另一种实现相同结果的方法。 .