I'm using flask as a python framework for my object detection REST API and it works just fine on MacOS. The application takes the uploaded image and it works on that. I'm sending a POST request to upload the image to the server. Just to give you an insight into my code:
#app.route('/post', methods=['GET', 'POST'])
def post():
form = PhotoForm(CombinedMultiDict((request.files, request.form)))
if request.method == 'POST' and form.validate():
with tempfile.NamedTemporaryFile() as temp:
form.input_photo.data.save(temp)
temp.flush()
print(temp.name)
result = detect_objects(temp.name)
photo_form = PhotoForm(request.form)
return render_template('upload.html',
photo_form=photo_form, result=result)
else:
return redirect(url_for('upload'))
However, when I try to run the same application on Windows 10, I get the following server error 500:
127.0.0.1 - - [08/Feb/2018 15:32:24] "GET / HTTP/1.1" 200 -
C:\Users\KUGUOG~1.KAA\AppData\Local\Temp\tmpw6y5g2f9
[2018-02-08 15:32:37,369] ERROR in app: Exception on /post [POST]
Traceback (most recent call last):
File "c:\python36\lib\site-packages\flask\app.py", line 1982, in wsgi_app
response = self.full_dispatch_request()
File "c:\python36\lib\site-packages\flask\app.py", line 1614, in full_dispatch_request
rv = self.handle_user_exception(e)
File "c:\python36\lib\site-packages\flask\app.py", line 1517, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "c:\python36\lib\site-packages\flask\_compat.py", line 33, in reraise
raise value
File "c:\python36\lib\site-packages\flask\app.py", line 1612, in full_dispatch_request
rv = self.dispatch_request()
File "c:\python36\lib\site-packages\flask\app.py", line 1598, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "C:\Users\kuguoglu.berk.kaan\Desktop\ObjectDetectionRestApi\app.py", line 188, in post
result = detect_objects(temp.name)
File "C:\Users\kuguoglu.berk.kaan\Desktop\ObjectDetectionRestApi\app.py", line 149, in detect_objects
image = Image.open(image_path).convert('RGB')
File "c:\python36\lib\site-packages\PIL\Image.py", line 2543, in open
fp = builtins.open(filename, "rb")
PermissionError: [Errno 13] Permission denied: 'C:\\Users\\KUGUOG~1.KAA\\AppData\\Local\\Temp\\tmpw6y5g2f9'
127.0.0.1 - - [08/Feb/2018 15:32:37] "POST /post HTTP/1.1" 500 -
I skimmed through quite a few posts and forums and I thought this might be related to file permission in Windows OS. As it explicitly says permission error and all the related posts I've read so far mentions file permissions I do not think that it's related to the program itself. If it was the case, it wouldn't work smoothly on MacOS in the first place.
So far, I have tried listening to different ports, including 80 and 8080, and running the program as an administrator through PyCharm terminal and command prompt. However, these did not solve the issue.
I'm using Python 3.6.3, Flask 0.12.2, in case it helps you figure out the issue. Feel free to ask me for more details, if needed. I'd be happy to provide if I can.
Cheers.
Edit: I tried some of the suggested ways in the following two posts, however, all of them failed.
How to run python script with elevated privileges on Windows
Request UAC elevation from within python scripts - 1
Request UAC elevation from within python scripts - 2
PermissionError: [Errno 13] Permission denied
Further, I disabled read-only option for the directory below to see if it solves the problem but it didn't.
C:\Users\KUGUOG~1.KAA\AppData\
Are you running with pycharm?
If you are running with cmd, run the command first as administrator.
When you find the cmd.exe, right click it and click on run as administrator
Elif you are using pycharm, run it as administrator as well.
Related
This question already has an answer here:
Refering to a directory in a Flask app doesn't work unless the path is absolute
(1 answer)
Closed 1 year ago.
Alright, I'm creating a Python project of mine using my two favorite modules. Flask and discord. Now thus to say, I'm not the best, but I'm encountering a new error when trying to create a new file when directory is empty of said name. Here's the error I'm getting:
2.168.0.26 - - [18/Jun/2021 21:30:42] "GET / HTTP/1.1" 404 -
Trying to open Mewniverse's folder
File not found error raised
File not accessible. creating new.
[2021-06-18 21:30:42,559] ERROR in app: Exception on /favicon.ico [GET]
Traceback (most recent call last):
File "/data/user/0/ru.iiec.pydroid3/files/aarch64-linux-android/lib/python3.8/site-packages/flask/app.py", line 2070, in wsgi_app
response = self.full_dispatch_request()
File "/data/user/0/ru.iiec.pydroid3/files/aarch64-linux-android/lib/python3.8/site-packages/flask/app.py", line 1515, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/data/user/0/ru.iiec.pydroid3/files/aarch64-linux-android/lib/python3.8/site-packages/flask/app.py", line 1513, in full_dispatch_request
rv = self.dispatch_request()
File "/data/user/0/ru.iiec.pydroid3/files/aarch64-linux-android/lib/python3.8/site-packages/flask/app.py", line 1499, in dispatch_request
return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args)
File "<string>", line 53, in hello_world
OSError: [Errno 30] Read-only file system: '/Mewniverse'
192.168.0.26 - - [18/Jun/2021 21:30:42] "GET /favicon.ico HTTP/1.1" 500 -
Now here's my code(ignoring indentation and unfinished parts as it is heavily unfinished):
def hello_world(ID):
print(f"Trying to open {ctx.author.name}'s folder")
directory = f'/{ctx.author.name}'
parent_dir = 'userFiles/templates'
path = os.path.join(parent_dir, directory)
if os.path.isfile(path):
print ("File exist")
else:
print(f'File not found error raised')
print("File not accessible. creating new.")
f = open(path, "w")
f.write("Now the file has more content!")
f.close()
print("Directory created and written in")
return render_template(f'{ctx.author.name}.html')
app.run(host='0.0.0.0', port=8080)
await ctx.message.channel.send(f'Here you go {ctx.author.name}! Your site will be here: http://192.168.0.26:8080/{ctx.author.name}')
I've been stuck here for a few hours, so I'm hoping someone could help find a solution quickly. Thanks if possible.
Answer from the comments:
How are you executing the script? Are you calling it directly, or via a service or something? Because when calling a script as a service, you need to give the absolute path to the files you want to work with. If your OS thinks that path is an absolute path, it will try to access something with very high privileges on the file tree, which might cause the problem. – itzFlubby
Its 5 in the morning and i need sleep. So i just copied the answer down for you all to understand this is the fix. Thanks a lot <3
I have a small flask server I'm running mostly for experimenting and tools I'm developing for self use (on my home network). It is running on development mode on a raspberry pi machine. It is configured to launch on startup via rc.local:
sudo -H -u pi /home/pi/Server/start.sh &
and the start.sh file reads
#!/bin/bash
cd /home/pi/Server
source /home/pi/Server/venv/bin/activate
export FLASK_APP=/home/pi/Server/app.py
export FLASK_ENV=development
export FLASK_RUN_HOST=192.168.1.104
export FLASK_RUN_PORT=5001
flask run
At the first couples of days everything was running fine, but now I get the following error:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/flask/app.py", line 2309, in __call__
return self.wsgi_app(environ, start_response)
File "/usr/lib/python3/dist-packages/flask/app.py", line 2295, in wsgi_app
response = self.handle_exception(e)
File "/usr/lib/python3/dist-packages/flask/app.py", line 1741, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/lib/python3/dist-packages/flask/_compat.py", line 35, in reraise
raise value
File "/usr/lib/python3/dist-packages/flask/app.py", line 2291, in wsgi_app
ctx.push()
File "/usr/lib/python3/dist-packages/flask/ctx.py", line 377, in push
self.app, self.request
File "/usr/lib/python3/dist-packages/flask/sessions.py", line 343, in open_session
data = s.loads(val, max_age=max_age)
File "/usr/lib/python3/dist-packages/itsdangerous.py", line 643, in loads
.unsign(s, max_age, return_timestamp=True)
File "/usr/lib/python3/dist-packages/itsdangerous.py", line 466, in unsign
return value, self.timestamp_to_datetime(timestamp)
File "/usr/lib/python3/dist-packages/itsdangerous.py", line 404, in timestamp_to_datetime
return datetime.utcfromtimestamp(ts + EPOCH)
OverflowError: timestamp out of range for platform time_t
From what I see here This is an issue of browser cache. How can I tell flask to cope with this?
Looks like you're using sessions/cookies? Try looking into that, maybe the date isn't proper or invalid. Try clearing it session.clear() or use a shorter expiration date. I've also had issues after upgrading from python 2 to 3 that messed up the cookies, if you've done that, you need to clear your cache so python3 date/time cookies can be set.
This seems to be an error when time returned is 0 from this Adafruit CircuitPython NTP issue. A direct approach would be to patch some flask dependencies with a PR.
However this seems more to be an error with your cache age. Try reducing it to a short time
#app.after_request
def after_request(response):
response.headers["Cache-Control"] = "max-age=300" # in second
return response
What I am trying to achieve is pretty simple.
I want to use Flask to create a web app that connects to a remote Server via API calls (specifically ParseServer).
I am using a third-party library to achieve this and everything works perfectly when I am running my code in a stand-alone script. But when I add my code into the Flask I suddenly can't authenticate with the Server
Or to be more precise I get an 'unauthorized' error when executing an API call.
It seems to me that in Flask, the registration method used by the APi library is not remembered.
I tried many things of putting the registration and initialization code in different places in Flask, nothing worked.
I asked a similar question in the Github of the Library with no help.
So I guess I have two questions that could help me solve this
1) Where should I put a registration method and import of the files from this library?
&
2) What can I do to identify the issue specifically, eg. to know precisely what's wrong?
Here's some code
The Flask code is here
#app.route('/parseinsert')
def run_parse_db_insert():
"""The method for testing implementation and design of the Parse Db
"""
pc = ParseCommunication()
print(pc.get_all_names_rating_table())
return 'done'
The ParseCommunication is my Class that deals with Parse. If I run ParseCommunication from that script, with the same code as above in the main part, everything works perfectly.
I run the Flask app with dev_appserver.py from Google App Engine.
My folder structure
/parseTest
/aplication
views.py
app.yaml
run.py
My run.py code
import os
import sys
sys.path.insert(1, os.path.join(os.path.abspath('.'), 'lib'))
sys.path.insert(1, os.path.join(os.path.abspath('.'), 'application'))
import aplication
Let me know what else I could provide to help out.
Thank you in Advance
EDIT:
A stack trace as requested.
It's mostly related to the library (from what I can say?)
ERROR 2016-09-28 06:45:50,271 app.py:1587] Exception on /parseinsert [GET]
Traceback (most recent call last):
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/flask/app.py", line 1988, in wsgi_app
response = self.full_dispatch_request()
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/flask/app.py", line 1641, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/flask/app.py", line 1544, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/flask/app.py", line 1639, in full_dispatch_request
rv = self.dispatch_request()
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/flask/app.py", line 1625, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/home/theshade/Devel/ParseBabynames/parseTest/aplication/views.py", line 34, in run_parse_db_insert
name = pc.get_user('testuser1')
File "/home/theshade/Devel/ParseBabynames/parseTest/aplication/parseCommunication.py", line 260, in get_user
return User.Query.get(username=uname)
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/parse_rest/query.py", line 58, in get
return self.filter(**kw).get()
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/parse_rest/query.py", line 150, in get
results = self._fetch()
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/parse_rest/query.py", line 117, in _fetch
return self._manager._fetch(**options)
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/parse_rest/query.py", line 41, in _fetch
return [klass(**it) for it in klass.GET(uri, **kw).get('results')]
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/parse_rest/connection.py", line 108, in GET
return cls.execute(uri, 'GET', **kw)
File "/home/theshade/Devel/ParseBabynames/parseTest/lib/parse_rest/connection.py", line 102, in execute
raise exc(e.read())
ResourceRequestLoginRequired: {"error":"unauthorized"}
Parse requires keys and env variables. Check this line:
API_ROOT = os.environ.get('PARSE_API_ROOT') or 'https://api.parse.com/1'
Your error is in line 102 at:
https://github.com/milesrichardson/ParsePy/blob/master/parse_rest/connection.py
Before you can parse, you need to register:
from parse_rest.connection import register
APPLICATION_ID = '...'
REST_API_KEY = '...'
MASTER_KEY = '...'
register(APPLICATION_ID, REST_API_KEY, master_key=MASTER_KEY)
After updating from 1.7.5 (where everything worked fine) I'm getting a HTTP Error 403: Forbidden when trying to open any sites via localhost. Strange thing is I have pretty much the same setup at home as here at work and everything works there... Might be an issue with proxy server we're using at work, since that's the only difference I can think of? Here's the error log I'm getting, so if anyone knows what's going on please help (;
Traceback (most recent call last):
File "U:\Dev\GAE\lib\cherrypy\cherrypy\wsgiserver\wsgiserver2.py", line 1302, in communicate
req.respond()
File "U:\Dev\GAE\lib\cherrypy\cherrypy\wsgiserver\wsgiserver2.py", line 831, in respond
self.server.gateway(self).respond()
File "U:\Dev\GAE\lib\cherrypy\cherrypy\wsgiserver\wsgiserver2.py", line 2115, in respond
response = self.req.server.wsgi_app(self.env, self.start_response)
File "U:\Dev\GAE\google\appengine\tools\devappserver2\wsgi_server.py", line 246, in __call__
return app(environ, start_response)
File "U:\Dev\GAE\google\appengine\tools\devappserver2\request_rewriter.py", line 311, in _rewriter_middleware
response_body = iter(application(environ, wrapped_start_response))
File "U:\Dev\GAE\google\appengine\tools\devappserver2\python\request_handler.py", line 89, in __call__
self._flush_logs(response.get('logs', []))
File "U:\Dev\GAE\google\appengine\tools\devappserver2\python\request_handler.py", line 220, in _flush_logs
apiproxy_stub_map.MakeSyncCall('logservice', 'Flush', request, response)
File "U:\Dev\GAE\google\appengine\api\apiproxy_stub_map.py", line 94, in MakeSyncCall
return stubmap.MakeSyncCall(service, call, request, response)
File "U:\Dev\GAE\google\appengine\api\apiproxy_stub_map.py", line 320, in MakeSyncCall
rpc.CheckSuccess()
File "U:\Dev\GAE\google\appengine\api\apiproxy_rpc.py", line 156, in _WaitImpl
self.request, self.response)
File "U:\Dev\GAE\google\appengine\ext\remote_api\remote_api_stub.py", line 200, in MakeSyncCall
self._MakeRealSyncCall(service, call, request, response)
File "U:\Dev\GAE\google\appengine\ext\remote_api\remote_api_stub.py", line 226, in _MakeRealSyncCall
encoded_response = self._server.Send(self._path, encoded_request)
File "U:\Dev\GAE\google\appengine\tools\appengine_rpc.py", line 393, in Send
f = self.opener.open(req)
File "U:\Dev\Python\lib\urllib2.py", line 410, in open
response = meth(req, response)
File "U:\Dev\Python\lib\urllib2.py", line 523, in http_response
'http', request, response, code, msg, hdrs)
File "U:\Dev\Python\lib\urllib2.py", line 448, in error
return self._call_chain(*args)
File "U:\Dev\Python\lib\urllib2.py", line 382, in _call_chain
result = func(*args)
File "U:\Dev\Python\lib\urllib2.py", line 531, in http_error_default
raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
HTTPError: HTTP Error 403: Forbidden
INFO 2013-04-19 12:28:52,576 server.py:561] default: "GET / HTTP/1.1" 500 -
INFO 2013-04-19 12:28:52,619 server.py:561] default: "GET /favicon.ico HTTP/1.1" 304 -
Also, the launcher throws an error when closing:
Traceback (most recent call last):
File "launcher\mainframe.pyc", line 327, in OnStop
File "launcher\taskcontroller.pyc", line 167, in Stop
File "launcher\dev_appserver_task_thread.pyc", line 82, in stop
File "launcher\taskthread.pyc", line 107, in stop
File "launcher\platform.pyc", line 397, in KillProcess
pywintypes.error: (5, 'TerminateProcess', 'Access is denied.')
I had this very same issue with my MacOSX when using a proxy server using Google App Engine Launcher 1.8.6. Apparently there's an issue with "proxy_bypass" on "urllib2.py".
There are two possible solutions:
Downgrade to 1.7.5, but, who wants to downgrade?
Edit "[GAE Instalattion path]/google/appengine/tools/appengine_rpc.py" and look for the line that says
opener.add_handler(fancy_urllib.FancyProxyHandler())
In my computer it was line 578, and then put a hash (#) at the beginning of the line, like this:
`#opener.add_handler(fancy_urllib.FancyProxyHandler())`
Save the file, stop and then restart your application. Now dev_appserver.py shouldn't try to use any proxy server at all.
If your application uses any external resources like a SOAP Webservice or something like that and you can't reach the server without the proxy server, then you'll have to downgrade. Please keep in mind that external javascript files (like facebook SDK or similar) are loaded from your browser, not from your application.
Since I'm not using any external REST or SOAP services it worked for me!
Hopefully it will work for you as well.
Try either:
-Accessing it through a different proxy. I.E a . proxy within a proxy
-Accessing it through your local IP i.e 192.168.1.1
I faced the same issue with version 1.9.5. Seems that the API proxy is sending some RPCs to the proxy server, which are then being rejected with HTTP 403 (since proxy servers are generally configured to reject connection attempts to arbitrary ports). In my case I was using the urlfetch module in my app to access external web pages, so disabling the proxy server was not a choice for me.
This is how I worked around the issue some time back (most probably it was based on comments found under this issue, but I cannot remember the exact sources).
NOTE:
For this approach to work, you'll have to know the hostname/IP address and default port of your proxy server, and change them appropriately in the code if you happen to connect to a different proxy server.
When you are not behind the proxy server, you will have to revert the applied changes in order to return to a working state (if you want internet access inside your app).
Here it goes:
Disable proxy settings for the Python (Google App Engine Launcher) environment in some way. (In my case it was easy since I was launching the dev_appserver.py from a Terminal shell (on Linux), and the unset http_proxy and unset https_proxy commands did the trick.)
Edit {App Engine SDK root}/google/appengine/api/urlfetch_stub.py. Find the code block
if _CONNECTION_SUPPORTS_TIMEOUT:
connection = connection_class(host, timeout=deadline)
else:
connection = connection_class(host)
(lines 376-379 in my case) and replace it with:
if _CONNECTION_SUPPORTS_TIMEOUT:
if host[:9] == 'localhost' or host[:9] == '127.0.0.1':
connection = connection_class(host, timeout=deadline)
else:
connection = connection_class('your_proxy_host_goes_here', your_proxy_port_number_goes_here, timeout=deadline)
else:
if host[:9] == 'localhost' or host[:9] == '127.0.0.1':
connection = connection_class(host)
else:
connection = connection_class('your_proxy_host_goes_here', your_proxy_port_number_goes_here)
replacing the placeholders your_proxy_host_goes_here and your_proxy_port_number_goes_here with appropriate values.
(I believe this code can be written more elegantly, though... any Python geeks out there? :) )
In my case, I also had to delete the existing compiled file urlfetch_stub.pyc (located in the same directory as urlfetch_stub.py) because the SDK didn't seem to pick up the changes until I did so.
Now you can use dev_appserver to launch your app, and use urlfetch-backed services within the app, free from HTTP 403 errors.
I've got a Flask app that I'm trying to deploy using Gunicorn and nginx. However, although it works fine locally, it throws a TemplateNotFound error when I run in with Gunicorn on my remote server.
I'm not sure how to even start debugging this, let alone why it's failing...would love help on the former, if not the latter. I thought maybe it was a permissions issue, so chmod'd the templates folder to 777...no luck. Here's all the relavant details:
install script
Starting with a bare Ubuntu 10.04 install, I run this to set up the server and pull in my code: https://github.com/total-impact/total-impact-deploy/blob/master/deploy.sh. Then I put this nginx config file at /etc/nginx/sites-available/total-impact:
server {
location / {
proxy_pass http://127.0.0.1:8000;
}
}
Finally, I navigate the app directory and run gunicorn web:app, and hit the server's IP address. This generates a 500 in the browser, and this output on the command line:
stack trace:
root#jc:/home/ti/total-impact-webapp/totalimpactwebapp# gunicorn web:app2012-05-28 23:15:06 [15313] [INFO] Starting gunicorn 0.14.3
2012-05-28 23:15:06 [15313] [INFO] Listening at: http://127.0.0.1:8000 (15313)
2012-05-28 23:15:06 [15313] [INFO] Using worker: sync
2012-05-28 23:15:06 [15316] [INFO] Booting worker with pid: 15316
2012-05-28 23:15:12,274 - totalimpactwebapp.core - ERROR - Exception on / [GET]
Traceback (most recent call last):
File "/usr/local/lib/python2.6/dist-packages/flask/app.py", line 1292, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/lib/python2.6/dist-packages/flask/app.py", line 1062, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/local/lib/python2.6/dist-packages/flask/app.py", line 1060, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/local/lib/python2.6/dist-packages/flask/app.py", line 1047, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/home/ti/total-impact-webapp/totalimpactwebapp/web.py", line 60, in home
return render_template('index.html', commits=False)
File "/usr/local/lib/python2.6/dist-packages/flask/templating.py", line 120, in render_template
return _render(ctx.app.jinja_env.get_template(template_name),
File "/usr/local/lib/python2.6/dist-packages/jinja2/environment.py", line 719, in get_template
return self._load_template(name, self.make_globals(globals))
File "/usr/local/lib/python2.6/dist-packages/jinja2/environment.py", line 693, in _load_template
template = self.loader.load(self, name, globals)
File "/usr/local/lib/python2.6/dist-packages/jinja2/loaders.py", line 115, in load source, filename, uptodate = self.get_source(environment, name)
File "/usr/local/lib/python2.6/dist-packages/flask/templating.py", line 61, in get_source
raise TemplateNotFound(template)
TemplateNotFound: index.html
Are your templates in [app root]/templates/?
If so, check to be sure your path is correct. Put this as the first line in the view that handles your homepage:
return app.root_path
If that's what you expect to see - or if you're using Blueprints or another method that changes the default Jinja Environment somehow - it's a little more complicated.
Oddly, Jinja doesn't seem to have a jinja2.Environment.FileSystemLoader.get_search_path() method. I assumed it would have one :(
Today, I experienced identical problems after a long period of my Flask app behaving quite normally (ie not throwing TemplateNotFound exceptions). None of the approaches mentioned by others here hit the mark or seemed appropriate (eg app.debug, path manipulation).
Instead, I tracked it down to the standard Flask app initialisation line:
app = Flask(__name__)
I had changed __name__ to another value (to get access to a named logger), not expecting for all this carnage to unfold :-) Don't change this value unless you are very familiar with Flask internals.
I have just spent 2 hours in a very similar situation and thought I'd post what ended up being the solution.
I was suddenly getting TemplateNotFound errors in the Apache logs from my Flask application, in production, which had been running fine until then. This resulted in 500 errors across the site.
First issue was that the TemplateNotFound errors did not show unless I had Flask's "debug" flag on -- there was no sign of any problems at all in the Apache log despite LogLevel set to info.
Running the app "locally" (Flask listens on localhost:5000) was fine (one can test the pages via wget 127.0.0.0:5000). It turned out that a copy of the main web app python code had somehow landed in the directory above where it should have been. This was imported by wsgi first and, as a result, the relative path to templates was incorrect.