Custom error handler in flask_restful throws NameError - flask

I am trying to add a custom error code to a flask_restful API, following the directions given in the docs however I do not receive the correct response and I am getting a NameError: global name 'UnsupportedMediaType' is not defined message. What am I doing wrong here?
# -*- coding: utf-8 -*-
from flask import Flask, request
from flask_restful import Resource, Api
import service
errors = {
'UnsupportedMediaType': {
'message': 'Unsupported Media Type',
'status': 415
}
}
app = Flask(__name__)
api = Api(app, errors=errors)
class Service(Resource):
def post(self):
if request.is_json:
data = request.get_json()
return service.handler(args['data'])
else:
raise UnsupportedMediaType
api.add_resource(Service, '/')
if __name__ == '__main__':
app.run(host='0.0.0.0', debug=True)

You must store the error handler to a function. Like this:
def error(exception):
return {some json error data with the message 'exception'}
now you can call the error handler as you want.
OR
You can use Flask error handler decorator for that. Heres the link

Related

Getting 400 Bad Request from Open AI API using Python Flask

I want to get response using Flask from OpenAI API. Whether I am getting Status 400 Bad Request from Browser through http://127.0.0.1:5000/chat
Bad Request
The browser (or proxy) sent a request that this server could not understand.
Also I am checking this from Postman
from flask import Flask, request, render_template
import requests
app = Flask(__name__)
#app.route('/')
def index():
return 'Welcome to ChatGPT app!'
#app.route('/chat', methods=['GET', 'POST'])
def chat():
user_input = request.form['text']
# Use OpenAI's API to generate a response from ChatGPT
response = generate_response_from_chatgpt(user_input)
return response
def generate_response_from_chatgpt(user_input):
api_key = "YOUR_API_KEY"
url = "https://api.openai.com/v1/engines/davinci/completions"
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {api_key}"
}
data = {
"prompt": user_input,
"engine": "davinci"
}
response = requests.post(url, headers=headers, json=data)
return response.json()["choices"][0]["text"]
if __name__ == '__main__':
app.run()
It would be best if you check the openai documentation to make sure you are using the correct endpoint and data format in your request.
Also, you should check your API key, if it is correct and if you have reached the limit of requests.
Also, it's worth noting that the code you provided is missing the import statement for Flask. You will need to add the following line at the top of your file:
from flask import Flask, request
Also, I see that you're using request.form['text'] but you should check if the request is a GET or POST request.
if request.method == 'POST':
user_input = request.form['text']
else:
user_input = request.args.get('text')
This is to avoid a KeyError being raised when the request is a GET request.

Receiving CORS policy error when submitting form from Angular to flask application

I have tried several things but I am not able to figure this one out. I have a back-end flask app and a front-end client written in Angular. When I submit my register user form I get a cors error. I have read the documentation for flask_cors and have tried to get it to work but I still get the same error below:
Access to XMLHttpRequest at 'http://localhost:5000/v1/auth/register' from origin 'http://localhost:4200' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
Here is my app.py from the flask app.
Any help is greatly appreciated!
import os, sys
from flask import Flask
import pathlib
from flask_cors import CORS
from flask_restplus import Api, Resource, fields
from werkzeug.middleware.proxy_fix import ProxyFix
import coloredlogs, logging as log
coloredlogs.install()
from main.apis.user import api as User
from main.apis.auth import api as Auth
from main import create_app
from flask_pymongo import PyMongo
# Init app
app = Flask(__name__)
#cors = CORS(app, resources={r"*": {"origins": "*"}})
CORS(app, origins="http://localhost:4200", allow_headers=[
"Content-Type", "Authorization", "Access-Control-Allow-Credentials","Access-Control-Allow-Origin"],
supports_credentials=True, intercept_exceptions=False)
authorizations = {
'token': {
'type': 'apiKey',
'in': 'header',
'name': 'Authorization'
}
}
config_name = os.getenv('FLASK_CONFIG')
app = create_app(config_name)
api = Api(app, authorizations=authorizations, version='1.0', title='API docs',
description='A simple REST API with JWT authentication.',
doc='/docs'
)
app.config['jwt']._set_error_handler_callbacks(api)
app.config['ROOT_DIR'] = pathlib.Path(__file__).parent.absolute()
# #app.before_first_request
# this function is to init the db and realted models
# def create_tables():
# print("Before first statement")
# db.create_all()
# Endpoints
api.add_namespace(Auth, path='/v1')
api.add_namespace(User, path='/v1')
# Run Server
if __name__ == '__main__':
app.run()
adding this seemed to fix my issue.
#app.after_request
def after_request(response):
response.headers.add('Access-Control-Allow-Origin', '*')
response.headers.add('Access-Control-Allow-Headers', 'Content-Type')
return response
Looks like in your code you are creating app = Flask(__name__), applying the CORS to that variable and then over writing app by using app = create_app(config_name) a few lines later. So that causes your CORS setup on the first app to be lost.

module 'requests' has no attribute 'files'

Running the script gives below error :
AttributeError: module 'requests' has no attribute 'files'
Code is as follows :
import requests
app = Flask(__name__)
#app.route('/api/test/', methods=['POST'])
def test():
filesReceived = requests.files['file']
What I understand from your code, you are trying to get the file received by the request, right?
If that's what you want, you are using the wrong import.
Requests is an http library for python.
If you want the file sent in the request, you need to use request from flask.
So your code will be something like:
from flask import request
app = Flask(__name__)
#app.route('/api/test/', methods=['POST'])
def test():
filesReceived = request.files['file']

mailgun and flask forms

I keep getting the following error when I run my code:
TypeError: 'Response' object is not callable
Here is my code...
from flask import Flask, render_template, flash
import os
import requests
import forms
app = Flask(__name__)
app.secret_key = 'jfdsjajfjds'
mg_key = os.environ['MAILGUN_API_KEY']
#app.route("/", methods=('GET', 'POST'))
def landing():
form = forms.OptinForm()
if form.validate_on_submit():
return requests.post(
"https://api.mailgun.net/v3/lists/test_list#sandbox.mailgun.org/members",
auth=('api', 'mg_key'),
data={'subscribed': True,
'address': form.email.data,
'name': form.first_name.data})
flash("Thanks! Check your email.")
return render_template('landing.html', form=form)
if __name__ == "__main__":
app.run()
I figured out the problem. I was calling my API key variable as a string. fixed it by changing 'mg_key' to mg_key

How to test 500.html error page in django development env?

I am using Django for a project and is already in production.
In the production environment 500.html is rendered whenever a server error occurs.
How do I test the rendering of 500.html in dev environment? Or how do I render 500.html in dev, if I turn-off debug I still get the errors and not 500.html
background: I include some page elements based on a page and some are missing when 500.html is called and want to debug it in dev environment.
I prefer not to turn DEBUG off. Instead I put the following snippet in the urls.py:
if settings.DEBUG:
urlpatterns += patterns('',
(r'^500/$', 'your_custom_view_if_you_wrote_one'),
(r'^404/$', 'django.views.generic.simple.direct_to_template', {'template': '404.html'}),
)
In the snippet above, the error page uses a custom view, you can easily replace it with Django's direct_to_template view though.
Now you can test 500 and 404 pages by calling their urls: http://example.com/500 and http://example.com/404
In Django 1.6 django.views.generic.simple.direct_to_template does not exists anymore, these are my settings for special views:
# urls.py
from django.views.generic import TemplateView
from django.views.defaults import page_not_found, server_error
urlpatterns += [
url(r'^400/$', TemplateView.as_view(template_name='400.html')),
url(r'^403/$', TemplateView.as_view(template_name='403.html')),
url(r'^404/$', page_not_found),
url(r'^500/$', server_error),
]
And if you want to use the default Django 500 view instead of your custom view:
if settings.DEBUG:
urlpatterns += patterns('',
(r'^500/$', 'django.views.defaults.server_error'),
(r'^404/$', 'django.views.generic.simple.direct_to_template', {'template': '404.html'}),
)
Continuing shanyu's answer, in Django 1.3+ use:
if settings.DEBUG:
urlpatterns += patterns('',
(r'^500/$', 'django.views.defaults.server_error'),
(r'^404/$', 'django.views.defaults.page_not_found'),
)
For Django > 3.0, just set the raise_request_exception value to False.
from django.test import TestCase
class ViewTestClass(TestCase):
def test_error_page(self):
self.client.raise_request_exception = False
response = self.client.get(reverse('error-page'))
self.assertEqual(response.status_code, 500)
self.assertTrue(
'some text from the custom 500 page'
in response.content.decode('utf8'))
Documentation: https://docs.djangoproject.com/en/3.2/topics/testing/tools/
NOTE: if the error page raises an exception, that will show up as an ERROR in the test log. You can turn the test logging up to CRITICAL by default to suppress that error.
Are both debug settings false?
settings.DEBUG = False
settings.TEMPLATE_DEBUG = False
How i do and test custom error handlers
Define custom View based on TemplateView
# views.py
from django.views.generic import TemplateView
class ErrorHandler(TemplateView):
""" Render error template """
error_code = 404
template_name = 'index/error.html'
def dispatch(self, request, *args, **kwargs):
""" For error on any methods return just GET """
return self.get(request, *args, **kwargs)
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['error_code'] = self.error_code
return context
def render_to_response(self, context, **response_kwargs):
""" Return correct status code """
response_kwargs = response_kwargs or {}
response_kwargs.update(status=self.error_code)
return super().render_to_response(context, **response_kwargs)
Tell django to use custom error handlers
# urls.py
from index.views import ErrorHandler
# error handing handlers - fly binding
for code in (400, 403, 404, 500):
vars()['handler{}'.format(code)] = ErrorHandler.as_view(error_code=code)
Testcase for custom error handlers
# tests.py
from unittest import mock
from django.test import TestCase
from django.core.exceptions import SuspiciousOperation, PermissionDenied
from django.http import Http404
from index import views
class ErrorHandlersTestCase(TestCase):
""" Check is correct error handlers work """
def raise_(exception):
def wrapped(*args, **kwargs):
raise exception('Test exception')
return wrapped
def test_index_page(self):
""" Should check is 200 on index page """
response = self.client.get('/')
self.assertEqual(response.status_code, 200)
self.assertTemplateUsed(response, 'index/index.html')
#mock.patch('index.views.IndexView.get', raise_(Http404))
def test_404_page(self):
""" Should check is 404 page correct """
response = self.client.get('/')
self.assertEqual(response.status_code, 404)
self.assertTemplateUsed(response, 'index/error.html')
self.assertIn('404 Page not found', response.content.decode('utf-8'))
#mock.patch('index.views.IndexView.get', views.ErrorHandler.as_view(error_code=500))
def test_500_page(self):
""" Should check is 500 page correct """
response = self.client.get('/')
self.assertEqual(response.status_code, 500)
self.assertTemplateUsed(response, 'index/error.html')
self.assertIn('500 Server Error', response.content.decode('utf-8'))
#mock.patch('index.views.IndexView.get', raise_(SuspiciousOperation))
def test_400_page(self):
""" Should check is 400 page correct """
response = self.client.get('/')
self.assertEqual(response.status_code, 400)
self.assertTemplateUsed(response, 'index/error.html')
self.assertIn('400 Bad request', response.content.decode('utf-8'))
#mock.patch('index.views.IndexView.get', raise_(PermissionDenied))
def test_403_page(self):
""" Should check is 403 page correct """
response = self.client.get('/')
self.assertEqual(response.status_code, 403)
self.assertTemplateUsed(response, 'index/error.html')
self.assertIn('403 Permission Denied', response.content.decode('utf-8'))
urls.py
handler500 = 'project.apps.core.views.handler500'
handler404 = 'project.apps.core.views.handler404'
views.py
from django.template.loader import get_template
from django.template import Context
from django.http import HttpResponseServerError, HttpResponseNotFound
def handler500(request, template_name='500.html'):
t = get_template(template_name)
ctx = Context({})
return HttpResponseServerError(t.render(ctx))
def handler404(request, template_name='404.html'):
t = get_template(template_name)
ctx = Context({})
return HttpResponseNotFound(t.render(ctx))
tests.py
from django.test import TestCase
from django.test.client import RequestFactory
from project import urls
from ..views import handler404, handler500
class TestErrorPages(TestCase):
def test_error_handlers(self):
self.assertTrue(urls.handler404.endswith('.handler404'))
self.assertTrue(urls.handler500.endswith('.handler500'))
factory = RequestFactory()
request = factory.get('/')
response = handler404(request)
self.assertEqual(response.status_code, 404)
self.assertIn('404 Not Found!!', unicode(response))
response = handler500(request)
self.assertEqual(response.status_code, 500)
self.assertIn('500 Internal Server Error', unicode(response))
Update for Django > 1.6 and without getting
page_not_found() missing 1 required positional argument: 'exception'
Inspired by this answer:
# urls.py
from django.views.defaults import page_not_found, server_error, permission_denied, bad_request
[...]
if settings.DEBUG:
# This allows the error pages to be debugged during development, just visit
# these url in browser to see how these error pages look like.
urlpatterns += [
path('400/', bad_request, kwargs={'exception': Exception('Bad Request!')}),
path('403/', permission_denied, kwargs={'exception': Exception('Permission Denied')}),
path('404/', page_not_found, kwargs={'exception': Exception('Page not Found')}),
path('500/', server_error),
You can simply define the handler404 and handler500 for errors in your main views.py file as detailed in this answer:
https://stackoverflow.com/a/18009660/1913888
This will return the error that you desire when Django routes to that handler. No custom URL configuration is needed to route to a different URL name.
In Django versions < 3.0, you should do as follows:
client.py
from django.core.signals import got_request_exception
from django.template import TemplateDoesNotExist
from django.test import signals
from django.test.client import Client as DjangoClient, store_rendered_templates
from django.urls import resolve
from django.utils import six
from django.utils.functional import SimpleLazyObject, curry
class Client(DjangoClient):
"""Test client that does not raise Exceptions if requested."""
def __init__(self,
enforce_csrf_checks=False,
raise_request_exception=True, **defaults):
super(Client, self).__init__(enforce_csrf_checks=enforce_csrf_checks,
**defaults)
self.raise_request_exception = raise_request_exception
def request(self, **request):
"""
The master request method. Composes the environment dictionary
and passes to the handler, returning the result of the handler.
Assumes defaults for the query environment, which can be overridden
using the arguments to the request.
"""
environ = self._base_environ(**request)
# Curry a data dictionary into an instance of the template renderer
# callback function.
data = {}
on_template_render = curry(store_rendered_templates, data)
signal_uid = "template-render-%s" % id(request)
signals.template_rendered.connect(on_template_render,
dispatch_uid=signal_uid)
# Capture exceptions created by the handler.
exception_uid = "request-exception-%s" % id(request)
got_request_exception.connect(self.store_exc_info,
dispatch_uid=exception_uid)
try:
try:
response = self.handler(environ)
except TemplateDoesNotExist as e:
# If the view raises an exception, Django will attempt to show
# the 500.html template. If that template is not available,
# we should ignore the error in favor of re-raising the
# underlying exception that caused the 500 error. Any other
# template found to be missing during view error handling
# should be reported as-is.
if e.args != ('500.html',):
raise
# Look for a signalled exception, clear the current context
# exception data, then re-raise the signalled exception.
# Also make sure that the signalled exception is cleared from
# the local cache!
response.exc_info = self.exc_info # Patch exception handling
if self.exc_info:
exc_info = self.exc_info
self.exc_info = None
if self.raise_request_exception: # Patch exception handling
six.reraise(*exc_info)
# Save the client and request that stimulated the response.
response.client = self
response.request = request
# Add any rendered template detail to the response.
response.templates = data.get("templates", [])
response.context = data.get("context")
response.json = curry(self._parse_json, response)
# Attach the ResolverMatch instance to the response
response.resolver_match = SimpleLazyObject(
lambda: resolve(request['PATH_INFO'])
)
# Flatten a single context. Not really necessary anymore thanks to
# the __getattr__ flattening in ContextList, but has some edge-case
# backwards-compatibility implications.
if response.context and len(response.context) == 1:
response.context = response.context[0]
# Update persistent cookie data.
if response.cookies:
self.cookies.update(response.cookies)
return response
finally:
signals.template_rendered.disconnect(dispatch_uid=signal_uid)
got_request_exception.disconnect(dispatch_uid=exception_uid)
tests.py
from unittest import mock
from django.contrib.auth import get_user_model
from django.core.urlresolvers import reverse
from django.test import TestCase, override_settings
from .client import Client # Important, we use our own Client here!
class TestErrors(TestCase):
"""Test errors."""
#classmethod
def setUpClass(cls):
super(TestErrors, cls).setUpClass()
cls.username = 'admin'
cls.email = 'admin#localhost'
cls.password = 'test1234test1234'
cls.not_found_url = '/i-do-not-exist/'
cls.internal_server_error_url = reverse('password_reset')
def setUp(self):
super(TestErrors, self).setUp()
User = get_user_model()
User.objects.create_user(
self.username,
self.email,
self.password,
is_staff=True,
is_active=True
)
self.client = Client(raise_request_exception=False)
# Mock in order to trigger Exception and resulting Internal server error
#mock.patch('django.contrib.auth.views.PasswordResetView.form_class', None)
#override_settings(DEBUG=False)
def test_errors(self):
self.client.login(username=self.username, password=self.password)
with self.subTest("Not found (404)"):
response = self.client.get(self.not_found_url, follow=True)
self.assertNotIn('^admin/', str(response.content))
with self.subTest("Internal server error (500)"):
response = self.client.get(self.internal_server_error_url,
follow=True)
self.assertNotIn('TypeError', str(response.content))
Starting from Django 3.0 you could skip the custom Client definition and just use the code from tests.py.