indeed a very weird error I am dealing with. Weird because the same project is working fine when I am running it on localhost in pyCharm, however, when I uploaded all the files to EC2 server. I got the following error.
The project is running fine so I am able to host the application however when I send a post request I get HTTP ERROR CODE 500 as a response and following error in the console.
If someone could help me rectify this, I would be grateful
Traceback (most recent call last):
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/app.py", line 2464, in __cal l__
return self.wsgi_app(environ, start_response)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/app.py", line 2450, in wsgi_ app
response = self.handle_exception(e)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask_restful/__init__.py", line 2 72, in error_router
return original_handler(e)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/app.py", line 1867, in handl e_exception
reraise(exc_type, exc_value, tb)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/_compat.py", line 38, in rer aise
raise value.with_traceback(tb)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/app.py", line 2447, in wsgi_ app
response = self.full_dispatch_request()
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/app.py", line 1952, in full_ dispatch_request
rv = self.handle_user_exception(e)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask_restful/__init__.py", line 2 72, in error_router
return original_handler(e)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/app.py", line 1821, in handl e_user_exception
reraise(exc_type, exc_value, tb)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/_compat.py", line 38, in rer aise
raise value.with_traceback(tb)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/app.py", line 1950, in full_ dispatch_request
rv = self.dispatch_request()
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/app.py", line 1936, in dispa tch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask_restful/__init__.py", line 4 68, in wrapper
resp = resource(*args, **kwargs)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask/views.py", line 89, in view
return self.dispatch_request(*args, **kwargs)
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/flask_restful/__init__.py", line 5 83, in dispatch_request
resp = meth(*args, **kwargs)
File "/home/ubuntu/yAPI/resources/r_user.py", line 50, in post
user = user_schema.load(request.get_json())
File "/home/ubuntu/yAPI/yenv/lib/python3.6/site-packages/marshmallow_sqlalchemy/schema/load _instance_mixin.py", line 89, in load
raise ValueError("Deserialization requires a session")
ValueError: Deserialization requires a session
In my application, this is where the error was started.
class UserRegister(Resource):
@classmethod
def post(cls):
# the 'load' function in marshmallow will use the data to create usermodel object
user = user_schema.load(request.get_json())
As discussed in the comments, here is the solution so it can be helpful for other people:
You need to define a session and pass it to the load function like so:
from sqlalchemy import engine #thanks to your comment
from sqlalchemy.orm import scoped_session, sessionmaker
class UserRegister(Resource):
@classmethod
def post(cls):
# the 'load' function in marshmallow will use the data to create usermodel object
sess = scoped_session(sessionmaker(bind=engine))
user = user_schema.load(request.get_json(), sess)