AttributeError: 'Request' object has no attribute 'params' - python-3.x

I'm getting error " AttributeError: 'Request' object has no attribute 'params' " in falcon library on python3, ubuntu.
request url = 127.0.0.1:8000/user?name=abc
from wsgiref import simple_server
import falcon
class user(object):
def on_get(self, req, resp):
print(req.params['name'])
api = application = falcon.API()
usr = user()
api.add_route('/user', usr)
if __name__ == '__main__':
http = simple_server.make_server('127.0.0.10', 8000, api)
http.serve_forever()
In the above code I'm unable to access req.params

If you are using version 1.0, be aware of the following breaking change:
An option was added to toggle automatic parsing of form params. Falcon
will no longer automatically parse, by default, requests that have the
content type "application/x-www-form-urlencoded"...
Applications that require this functionality must re-enable it
explicitly, by setting a new request option that was added for that
purpose, per the example below:
app = falcon.API()
app.req_options.auto_parse_form_urlencoded = True
https://github.com/falconry/falcon/blob/master/CHANGES.rst

Related

Adding query parameter for every flask GET request

Trying to figure out the right mechanism to use here.
I want to modify the flask request coming in every time.
I think the request is immutable, so I am trying to figure out if this mechanism exists.
Basically, I want to append a string onto the end of the request coming in.
I can hook into the request and the right time in a before_request handler like this:
#app.before_app_request
def before_request_custom():
# Get the request
req = flask.request
method = str(req.method)
if method == "GET":
# Do stuff here
pass
But I am not sure what to actually do to add this in, and don't see a way to accomplish it...I guess i could redirect, but that seems silly in this case. Any ideas?
The request object is immutable (https://werkzeug.palletsprojects.com/en/1.0.x/wrappers/#base-wrappers), but request.args or request.form can be set from ImmutableOrderedMultiDict to just OrderedMultiDict using Subclassing on Flask (https://flask.palletsprojects.com/en/1.1.x/patterns/subclassing/). Here's an example of how you could add that filter[is_deleted]=False URL param:
from flask import Flask, request, Request
from werkzeug.datastructures import OrderedMultiDict
class MyRequest(Request):
parameter_storage_class = OrderedMultiDict
class MyApp(Flask):
def __init__(self, import_name):
super(MyApp, self).__init__(import_name)
self.before_request(self.my_before_method)
def my_before_method(self):
if "endpoint" in request.base_url:
request.args["filter[is_deleted]"] = "False"
app = MyApp(__name__)
app.request_class = MyRequest
#app.route('/endpoint/')
def endpoint():
filter = request.args.get('filter[is_deleted]')
return filter
This way you can modify request.args before you actually send the request.
How about this?
from flask import g
#app.before_request
def before_request():
# Get the request
req = flask.request
method = str(req.method)
if method == "GET":
g.my_addon = "secret sauce"
return None
Then, g.my_addon is available in every view function:
from flask import g
#app.route('/my_view')
def my_view():
if g.my_addon == "secret sauce":
print('it worked!')
Using test_request_context() you can make the trick.
Related: https://flask.palletsprojects.com/en/1.1.x/quickstart/#accessing-request-data

Apache Flink Stateful Function - Serialization problem?

I'm trying to build a project using an Apache Flink Stateful Function in Python, but I can't seem to get it to work. What I've narrowed the issue down to is that it seems when I send the request to my stateful function through my protobuf schema, the serializer is unable to serialize my message into the class I'm expecting. Here's what I'm trying to do:
import json
from statefun import StatefulFunctions, RequestReplyHandler
from jobs.session_event_pb2 import Event
functions = StatefulFunctions()
#functions.bind("namespace/funcname")
def funcname(context, session: Event):
print("hello world")
handler = RequestReplyHandler(functions)
if __name__ == '__main__':
inputFile = open("my_file.json", "r")
for line in inputFile:
data = json.loads(line).get('properties')
if data is not None and data.get('prop1') is not None and data.get('prop2') is not None:
request = Event()
request.prop1 = data["prop1"]
request.prop2 = data["prop2"]
request = request.SerializeToString()
handler(request)
Here's my Protobuf schema:
syntax = "proto3";
package mypackage;
message Event {
string prop1 = 1;
string prop2 = 2;
}
What am I doing wrong here?
That's because the RequestReply handler does not take direct protobuf messages. The Flink runtime sends a type called ToFunction and receives a response of type FromFunction. This payload contains your caller messages along with persisted values and other meta information.
If you can't to invoke the functions directly, such as in a test, I would encourage you to do that and not use the handler at all.

How to make put request with nested dictionaries to flask-restful?

The documentation example for a simple restful api is:
from flask import Flask, request
from flask_restful import Resource, Api
app = Flask(__name__)
api = Api(app)
todos = {}
class TodoSimple(Resource):
def get(self, todo_id):
return {todo_id: todos[todo_id]}
def put(self, todo_id):
todos[todo_id] = request.form['data']
return {todo_id: todos[todo_id]}
api.add_resource(TodoSimple, '/<string:todo_id>')
if __name__ == '__main__':
app.run(host="0.0.0.0",port="80",debug=True)
However, suppose I made a put request with a nested dictionary,ie {'data':{'fruit':'orange'}}. The TodoSimple would have request.form.to_dict() = {'data':'fruit'}. How can I work with the full nested dictionary?
You should probably use Schemas to achieve this goal. Take a good look at this first example of marshmallow docs:
https://marshmallow.readthedocs.io/en/3.0/
As flask-restful docs says:
The whole request parser part of Flask-RESTful is slated for removal
and will be replaced by documentation on how to integrate with other
packages that do the input/output stuff better (such as marshmallow).

how to use multiple dispatchers in same cherrypy application?

I have a cherrypy application like this:
import cherrypy
from controllers import UsersController
class Root(object):
exposed = True
def index(self):
return 'welcome'
if __name__ == '__main__':
root = Root()
root.users = UsersController()
cherrypy.tree.mount(
root,
'/',
{
'/users' : {'request.dispatch' : cherrypy.dispatch.MethodDispatcher()}
}
)
cherrypy.engine.start()
cherrypy.engine.block()
Now I wish to use MethodDispatcher() for providing REST api to /users resource and I want a default dispatcher for '/' path (where a call to root.index() is expected). Instead of writing own RoutesDispatcher() is there any way to achieve this? (e.g. using MethodDispatcher() for '/users' as shown and something like DefaultDispatcher() for '/')? BTW, the error I am getting is 'Root' object is not callable.
Since your Root is to be served with a normal dispatcher, it should be index.exposed = True.

CherryPy server name tag

When running a CherryPy app it will send server name tag something like CherryPy/version.
Is it possible to rename/overwrite that from the app without modifying CherryPy so it will show something else?
Maybe something like MyAppName/version (CherryPy/version)
This can now be set on a per application basis in the config file/dict
[/]
response.headers.server = "CherryPy Dev01"
Actually asking on IRC on their official channel fumanchu gived me a more clean way to do this (using latest svn):
import cherrypy
from cherrypy import _cpwsgi_server
class HelloWorld(object):
def index(self):
return "Hello World!"
index.exposed = True
serverTag = "MyApp/%s (CherryPy/%s)" % ("1.2.3", cherrypy.__version__)
_cpwsgi_server.CPWSGIServer.environ['SERVER_SOFTWARE'] = serverTag
cherrypy.config.update({'tools.response_headers.on': True,
'tools.response_headers.headers': [('Server', serverTag)]})
cherrypy.quickstart(HelloWorld())
This string appears to be being set in the CherrPy Response class:
def __init__(self):
self.status = None
self.header_list = None
self._body = []
self.time = time.time()
self.headers = http.HeaderMap()
# Since we know all our keys are titled strings, we can
# bypass HeaderMap.update and get a big speed boost.
dict.update(self.headers, {
"Content-Type": 'text/html',
"Server": "CherryPy/" + cherrypy.__version__,
"Date": http.HTTPDate(self.time),
})
So when you're creating your Response object, you can update the "Server" header to display your desired string. From the CherrPy Response Object documentation:
headers
A dictionary containing the headers of the response. You may set values in
this dict anytime before the finalize phase, after which CherryPy switches
to using header_list ...
EDIT: To avoid needing to make this change with every response object you create, one simple way to get around this is to wrap the Response object. For example, you can create your own Response object that inherits from CherryPy's Response and updates the headers key after initializing:
class MyResponse(Response):
def __init__(self):
Response.__init__(self)
dict.update(self.headers, {
"Server": "MyServer/1.0",
})
RespObject = MyResponse()
print RespObject.headers["Server"]
Then you can can call your object for uses where you need to create a Response object, and it will always have the Server header set to your desired string.

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