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NameError: name 'user_id' is not defined. For no apparent reason [closed]

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Error description
I would fire up the server program, and fire a request (GET) at the path /test_connection which is the path used by the client to test the server IP address btw. The server would then respond by printing out the traceback below in the console, the one line in particular that I can't get my head around is NameError: name 'user_id' is not defined as the variable is not even included in the response function for the path /test_connection (connection_test()). I know the error is on the server side as it will print out 'INTERNAL SERVER ERROR: 500' on the client code, so I didn't feel the necessity to include the client code.
Additional info:
Python version: 3.7
OS: Windows 10
Server Library: Flask
Traceback from error:
Traceback (most recent call last):
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 2309, in __call__
return self.wsgi_app(environ, start_response)
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 2295, in wsgi_app
response = self.handle_exception(e)
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1741, in handle_exception
reraise(exc_type, exc_value, tb)
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\_compat.py", line 35, in reraise
raise value
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 2292, in wsgi_app
response = self.full_dispatch_request()
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1815, in full_dispatch_request
rv = self.handle_user_exception(e)
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1718, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\_compat.py", line 35, in reraise
raise value
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1813, in full_dispatch_request
rv = self.dispatch_request()
File "C:\Users\sccre\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1799, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "E:\USB Stick Files\Programming\Python\Chat Room Thingy\server.py", line 19, in connection_test
message_dict[user_id]
NameError: name 'user_id' is not defined
Server code
from flask import Flask, request
from threading import Thread
import json
app = Flask(__name__)
message_dict = {}
ids = -1
#app.route('/test_connection')
def connection_test():
global ids
print('Connection tested from: {}'.format(request.remote_addr))
ids += 1
id_sent = str(ids)
return '{}'.format(id_sent)
#app.route('/new_message', methods=['POST'])
def new_message():
global message_dict
message_text = request.form['message']
user_id = request.form['id']
try:
message_dict[user_id]['message'] = message_text
except:
message_dict[user_id] = None
message_dict[user_id]['message'] = message_text
return '0'
#app.route('/chat')
def chat():
return json.dumps(message_dict)
if __name__ == '__main__':
app.run(debug=True, host='0.0.0.0')
Any help with this would be greatly appreciated.
Oscar.

Okay, The code is working completely fine to me.
Try one of the following :
1.Change your current File ( copy the contents to another )
2.Make the variable global.
3.Run the file directly from command prompt/shell (sometimes helpful)
4.Make sure your interpreter is ok

Oauth2 in Python with Flask gets 302 from API

I am trying to access MeisterTask's API with Python and Flask, and no matter what I do, I seem to always get a 302 code in return from the API, although I can get an access token (or so I think). Here is the code I have so far (I tried reducing it, this is the smallest snippet I could get that replicates the error):
from flask import Flask, redirect, url_for, session, request, jsonify
from flask_oauthlib.client import OAuth
app = Flask(__name__)
app.debug = True
app.secret_key = "development"
oauth = OAuth(app)
meistertask = oauth.remote_app(
'meistertask',
consumer_key= "XXXXXX",
consumer_secret= "XXXXXX",
request_token_params={"scope" : "meistertask"},
base_url='https://www.meistertask.com/api',
request_token_url=None,
access_token_method='GET',
access_token_url='https://www.mindmeister.com/login/oauth2/token',
authorize_url='https://www.mindmeister.com/oauth2/authorize'
)
#app.route('/')
def index():
if 'meistertask_token' in session:
me = meistertask.get('user')
return jsonify(me.data)
return redirect(url_for('login'))
#app.route('/login')
def login():
return meistertask.authorize(callback=url_for('authorized', _external=True))
#app.route('/logout')
def logout():
session.pop('meistertask_token', None)
return redirect(url_for('index'))
#app.route('/login/authorized')
def authorized():
resp = meistertask.authorized_response()
print(resp.get('code'))
if resp is None or resp.get('code') is None:
return 'Access denied: reason=%s error=%s resp=%s' % (
request.args['error'],
request.args['error_description'],
resp
)
session['meistertask_token'] = (resp['code'], '')
return "Hello"
#meistertask.tokengetter
def get_meistertask_oauth_token():
return session.get('meistertask_token')
if __name__ == "__main__":
app.run()
And here is the traceback:
flask_oauthlib.client.OAuthException: Invalid response from meistertask
Traceback (most recent call last):
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 2309, in __call__ return self.wsgi_app(environ, start_response)
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 2295, in wsgi_app response = self.handle_exception(e)
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1741, in handle_exception reraise(exc_type, exc_value, tb)
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\_compat.py", line 35, in reraise raise value
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 2292, in wsgi_app response = self.full_dispatch_request()
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1815, in full_dispatch_request rv = self.handle_user_exception(e)
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1718, in handle_user_exception reraise(exc_type, exc_value, tb)
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\_compat.py", line 35, in reraise raise value
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1813, in full_dispatch_request rv = self.dispatch_request()
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask\app.py", line 1799, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args)
File "~\Documents\MeisterTaskServer\hello.py", line 49, in authorized resp = meistertask.authorized_response()
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask_oauthlib\client.py", line 707, in authorized_response data = self.handle_oauth2_response(args)
File "~\AppData\Local\Programs\Python\Python37-32\lib\site-packages\flask_oauthlib\client.py", line 692, in handle_oauth2_response
Things I have tried
Tried to modify the method to get the access token from GET to POST. The API clearly states that I should use GET, yet every other example I have seen on flask_oauthlib's GitHub uses POST (the examples are 3 years old, but some still work, namely the GitHub one). Either give the same result.
Tried doing it barebones, without any library. The resulting code was thrice as long and also had more problems.
Used Django instead of Flask. Never even managed to get the hello world example going, it was too much work, and also I have discovered the library flask_oauthlib.
Things worth mentioning
I derived this code from this here GitHub example
There is also code there I omitted in order to keep the snippet short, that establishes that the server should use SSL (as per the request from the API that the redirect_uri should use HTTPS)
The app manages to redirect me over at MeisterTask and asks for my permission. Once I grant it, it redirects to "https://127.0.0.1:5000/login/authorized?code=some_token" where I get the traceback. If I look with Chrome's debugging tools to the requests made and what I receive, I see that I get an 302 from the API, but I also get an access token.
I run Windows 10 with Python 3.7.0
So what's the deal? What's the next step here? I've run out of things to try. Thank you for taking the time to solve this!

Flask: requests to subdirectory of static return 500

I'm aware that once I have everything up and running on a production server, nginx or apache are supposed to be serving static assets instead of Flask. In the interest of getting started quickly though, I'm running into an issue with Flask and requests to files in subdirectories of static.
A request for /static/test.css returns correctly, but a request for /static/test/test.css returns a 500 and throws this exception:
Traceback (most recent call last):
File "/home/tim/shadowcraft-ui-python/venv/lib/python3.5/site-packages/flask/app.py", line 1991, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/home/tim/shadowcraft-ui-python/venv/lib/python3.5/site-packages/flask/app.py", line 1567, in handle_exception
reraise(exc_type, exc_value, tb)
File "/home/tim/shadowcraft-ui-python/venv/lib/python3.5/site-packages/flask/_compat.py", line 33, in reraise
raise value
File "/home/tim/shadowcraft-ui-python/venv/lib/python3.5/site-packages/flask/app.py", line 1988, in wsgi_app
response = self.full_dispatch_request()
File "/home/tim/shadowcraft-ui-python/venv/lib/python3.5/site-packages/flask/app.py", line 1642, in full_dispatch_request
response = self.make_response(rv)
File "/home/tim/shadowcraft-ui-python/venv/lib/python3.5/site-packages/flask/app.py", line 1731, in make_response
raise ValueError('View function did not return a response')
ValueError: View function did not return a response
A bit of searching on that error returns mostly simple cases where someone forgot a return in a request handler, but nothing for when making direct requests for assets. It also does the same thing if trying to use url_for in a template to request the file from the subdirectory.

This ended up being an error in my code. I have a route handler that takes three parts as arguments, and since that handler isn't implemented yet, it caused Flask to throw the exception above. I ended up implementing the solution from Does Flask support regular expressions in its URL routing? for that handler since I know the first part is always one of a few different values, and the static handler can run as normal.

Inexplicable TypeError in python that does not contain any of my code in the traceback

This bug is driving me nuts. I am trying to create the backend of a website in python using flask. I am getting the following error and traceback:
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1478, in full_dispatch_request
response = self.make_response(rv)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1577, in make_response
rv = self.response_class.force_type(rv, request.environ)
File "/usr/local/lib/python2.7/dist-packages/werkzeug/wrappers.py", line 827, in force_type
response = BaseResponse(*_run_wsgi_app(response, environ))
File "/usr/local/lib/python2.7/dist-packages/werkzeug/test.py", line 855, in run_wsgi_app
app_iter = app(environ, start_response)
TypeError: 'int' object is not callable
Bizarrely, the traceback does not contain any of my files so I can't figure out what's causing it or how to fix it.
Here are the relevant methods that I wrote:
#app.route('/notes/<filenum>', methods=['GET', 'POST'])
def view(filenum):
if request.method == 'GET':
pass
else:
if 'username' in session:
if request.values['fnct'] == "delete":
asdf = database.delNote(filenum,session['username'])
return asdf
return "invalid command"
else:
return "not logged in"
def delNote(self, noteid,username):
try:
if self.getPost(noteid)[7] == self.usernameToID(username):
for file in glob.glob('uploads/' + str(noteid)+"-*"):
os.remove(file)
self._execute('DELETE FROM Posts where postID=?',(noteid,))
return 1
else:
return -2 #autherror
except IndexError:
return -1 #note does not exist
When I call delNote(), it works flawlessly without any errors. When I run view(filenum) with the line that calls delNote() commented out, it works flawlessly with no errors. When I call delNote from view, then I get the above error.
It seems that in spite of the error, the function does complete it's intended task. Using print statements, I figured out the entirety of view() runs before the error, but the error is thrown before the return asdf line is run. Can someone please explain to me what is going on because I'm resisting the growing temptation of throwing my computer out the window.
Thanks in advance

The short answer is, you're returning an integer from your controller and Flask doesn't support that.
Here's the relevant docs:
http://flask.pocoo.org/docs/0.10/api/#flask.Flask.make_response
Controllers must return a Response object or a string (or a few other specialized things). You can't return integers, they don't work. That error is because Flask can't figure out what to do with it, so it's assuming it's a callable, and ints are not callables.
The hacktaculuar way of solving your problem is just return str(asdf), but don't do that. It looks like you're trying to show error codes, so you almost certainly want to use the Flask abort() function instead and return the appropriate HTTP status.

Looking at your view procedure, I see the following:
asdf = database.delNote(filenum,session['username'])
There is no return value from the delNote method, so you're assigning None to asdf. I'm not familiar with Flask, but it's probably doing something with that value that it ultimately can't handle. The error you're getting about an int not being callable makes sense then, as None can be coerced to the integer 0. There's no need to assign your delNote to anything. Try this and see if it makes a difference:
database.delNote(filenum, session['username'])
return "Note deleted."

request.environ['HTTP_REFERER'] is None

i want to get HTTP_REFERER in python flask framework.
My route is this:
#app.route('/login')
def login():
if authenticateForPanel():
return redirect(url_for("panel"))
else:
ref = request.environ['HTTP_REFERER']
return render_template('login.html',blogOptions = g.blogOptions,ref=ref)
When i execute this,i got KeyError: 'HTTP_REFERER' with the traceback:
Traceback (most recent call last):
File "/Users/ozcan/flask/flask/app.py", line 1823, in __call__
return self.wsgi_app(environ, start_response)
File "/Users/ozcan/flask/flask/app.py", line 1811, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/Users/ozcan/flask/flask/app.py", line 1809, in wsgi_app
response = self.full_dispatch_request()
File "/Users/ozcan/flask/flask/app.py", line 1482, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/Users/ozcan/flask/flask/app.py", line 1480, in full_dispatch_request
rv = self.dispatch_request()
File "/Users/ozcan/flask/flask/app.py", line 1466, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/Users/ozcan/Documents/python/app.py", line 318, in login
ref = request.environ['HTTP_REFERER']
KeyError: 'HTTP_REFERER'
When i first wrote this code it was working.I do not directly call this url.I call localhost:5000/panel and it redirects me to the login method.So basically there should be a referer,am i wrong?
When i print the request.environ['HTTP_REFERER'] it prints None
I also tried with the
ref = request.referrer but it is None
Why it can be happen?Thanks a lot.

The werkzeug Request wrapper, which flask uses by default, does this work for you: request.referrer
from flask import Flask, request
import unittest
app = Flask(__name__)
#app.route('/')
def index():
return unicode(request.referrer)
class Test(unittest.TestCase):
def test(self):
c = app.test_client()
resp = c.get('/', headers={'Referer': '/somethingelse'})
self.assertEqual('/somethingelse', resp.data)
if __name__ == '__main__':
unittest.main()
But in the more general case, to retrieve the value of a dictionary key specifying a default if the key is not present, use dict.get

When i first wrote this code it was working.I do not directly call
this url.I call localhost:5000/panel and it redirects me to the login
method.So basically there should be a referer,am i wrong?
This is not correct. A redirect does not guarantee a referrer. Whether a browser will provide a referrer is browser-specific. Perhaps you were using a different browser that had this behavior at one point? The code you have now is working as best as it can be expected to.
See Will a 302 redirect maintain the referer string?

The only way I could get request.referrer to not be None is to load the page through . Redirecting and making regular old HTTP requests did not include a referrer attribute.

#dm03514 has the right idea, but if you're insistent upon using the environ dictionary, you should be using the get method. Also, how are you testing that it is None, i.e., are you using the interactive interpreter to print the value or are you adding print statements in the body?
An example of how you would do this reasonably:
# snip
else:
ref = request.environ.get('HTTP_REFERER')
# You can specify a default return value other than None like so:
# ref = request.environ.get('HTTP_REFERER', '/')
# snip