I packed some defs in a class to do a work of translation text into the other language using Bing or Google translation API. and using a Flask to render templates as you may aware of.
However, when do the translation, I have some status and progress information, like completed 10% and etc during translate the paragraphs. but that information generated in the translation class as you may imagine - the class does the translation job.
However, in my Flask app, after call the class do the translation I want to have an ajax call from the webpage to the Flask App to retrieve that 10% information which generated from that class.
Here is what I did:
If I don't use any class, put all the defs within the main Flask App file, I can use the a global variable store the 10% information, but that makes the codes complex and I want to pack all the associated defs in a class.
in the Flask App, I was trying to use session['translation_pos'] to retrieve the information that I stored in session['translation_pos'] in the class, but it seems not works.
I use python 3 and Flask, I don't know how to get this progress percentage information from the class - where the data generated - to the App.
May be one of the way would like store the number in a text file or some places, and read the file in the App, but I was thinking that certainly shouldn't the way to handle this problems.
Would anyone could advise with some idea that will be much appreciated.
Thank you All.
You may want to look at a different approach to running the task, using something like Celery or Redis Queue - covered very well here in the mega tutorial.
By using one of these, you can run the task and query the runner periodically for progress to report it back to the user.
If it were me, for the data processing I would store this in a database. When the task is completed, it gets re-queried and passed through to the UI as a template variable (or streamed from an ajax function if it's a large data set).
Related
I'm trying to add real-time features to my Django webapp. Basically, i want to show real time data on a webpage.
I have an external Python script which generates some JSON data, not big data but around 10 records per second. On the other part, i have a Django app, i would like my Django app to receive that data and show it on a HTML page in real time. I've already considered updating the data on a db and then retrieving it from Django, but i would have too many queries, since Django would query the DB 1+ times per second for every user and my external script would be writing a lot of data every second.
What i'm missing is a "central" system, a way to make these two pieces communicate. I know the question is probably not specific enough, but is there some way to do this? I know something about Django Channels, but i don't know if i could do what i want with it; i've also considered updating the data on a RabbitMQ queue and then retrieve it from Django, but this is not the best use of RabbitMQ.
So is there a way to do this with Django-Channels? Any kind of advice is appreciated.
I would suggest using Django Channels. You can also use Redis instead of RabbitMQ. In your case, Redis might be a better choice.
Here is an approach: http://www.maxburstein.com/blog/realtime-django-using-nodejs-and-socketio/
I am writing some unit-tests for an app. One of the features of this app is that it allows the user to upload videos to the server (or S3, depending on the configuration).
The difficulty I am having is coming up with a meaningful unit-test for this. So, the question is two-fold. First, what is a solid way to test this functionality?
Second, the following test fails because videofile entry in the dictionary is a string. Having done prints, I can see that in a real upload it is actually of type <class django.db.models.fields.files.FieldFile>. How should one go about creating this in a test to make the types similar to the real upload via the browser?
class VideoFormTest(TestCase):
def test_upload_form_valid(self):
form = VideoForm(data={'title':"Test Video Title", 'videofile':"videos/navigator.mp4"})
self.assertTrue(form.is_valid())
I've recently started working with Django. I'm working on an existing Django/Python based site. In particular I'm implementing some functionality to create and display a PDF document when a particular URL is hit. I have an entry in the app's urls file that routes to a function in the views file and the PDF generation is working fine.
However, the view function is pretty big and I want to extract the code out somewhere to keep my view as thin as possible, but I'm not sure of the best/correct approach. I'll probably need to generate other PDFs in due course so would it make sense to create a 'pdfs' app and put code in there? If so, should it go in a model or view?
In a PHP/CodeIgniter environment for example I would put the code into a model, but models seem to be closely linked to database tables in Django and I don't need any db functionality for this.
Any pointers/advice from more experienced Django users would be appreciated.
Thanks
If you plan to scale your project, I would suggest moving it to a separate app. Generally speaking, generating PDFs based on an url hit directly is not the best thing to do performance-wise. Generating a PDF file is pretty heavy on you server, so if multiple people do it at the same time, the performance of your system will suffer.
As a first step, just put it in a separate class, and execute that code from the view. At some point you will probably want to do some permission checks etc - that stays in the view, while generation of the PDF itself will be cleanly separated.
Once you test your code, scale etc - then you can substitute that one line call in the view into putting the PDF generation in a queue and only pulling it once it's done - that will allow you to manage your computing powers better.
Yes you can in principle do it in an app (the concept of reusable apps is the basis for their existence)
However not many people do it/not many applications require it. It depends on how/if the functionality will be shared. In other words there must be a real benefit.
The code normally goes in both the view/s and in the models (to isolate code and for the model managers)
I am implementing a really lightweight Web Project, which has just one page, showing data in a diagram. I use Django as a Webserver and d3.js as plotting routine for this diagram. As you can imagine, there are just a few simple time series which have to be responded by Django server, so I was wondering if I simply could hold this variable in ram. My first test was positive, I had something like this in my views.py:
X = np.array([123,23,1,32,123,1])
#csrf_exempt
def getGraph(request):
global X
return HttpResponse(json.dumps(X))
Notice, X is updated by another function every now and then, but all user access is read-only. Do I have to deal with
security issues by defining a global variable?
inconsistencies in general?
I found a thread discussing global variables in Django, but in that case, the difficulty is of handling multiple write-access.
To answer potential questions on why I don't want store data in database: All data I got in my X is already stored in a huge remote database and this web app just needs to display data.
Storing it in a variable does indeed have threading implications (and also scalibility - what if you have two Django servers running the same app?). The advice from the Django community is don't!.
This sounds like a good fit for the Django cache system though. Just cache your getGraph view with #cache_page and the job is done. No need to use memcache, the built-in in-memory memory-cache cache-backend* will work fine. Put a very high number as the time-out on the cache (years).
This way you are storing the HTTP response (JSON) not the value of X. But from your code sample, that is not a problem. If you need to re-calculate X you need to re-calculate the JSON, and if you need to re-calculate the JSON you will need to re-calculate X.
https://docs.djangoproject.com/en/dev/topics/cache/?from=olddocs/
1 or just 'built-in memory backend', I couldn't resist
I'm writing a psychology experiment in Python, and I need to make it available as a web app. I've already got the Python basically working as a command-line program. On the recommendation of a CS buddy I'm using Django with a sqlite db. This is also working, my development server is up and the database tables are ready and waiting.
What I don't understand is how to glue these two pieces together. The Django tutorials I've found are all about building things like blogs, messaging systems or polls; systems based on sending form data. I can't do that, because I'm timing responses to presented stimuli in milliseconds - I need to build an interactive app that doesn't rely (during the exercise) on form POST data or URL changes.
In short: I have no idea how to go from my simple command line program to a "real time" interactive web application.
Maximum kudos for links to relevant tutorials! I will also really appreciate a high-level explanation of the concept I'm missing here.
(FYI, I asked a previous question (choice of database) about this project here)
You are going to need to use HTML/Javascript, and then you can collect and send the results to the server. The results can get gamed though, as the code for the exercise is going to be client side.
Edit: I recommend a Javascript library, jQuery: http://docs.jquery.com/Tutorials
Edit 2:
I'll be a bit more specific, you need at least two models in Django, Exercise, and ExecutedExercise. Exercise will have fields with its name, number, etc., generic data for each exercise. ExecutedExercise will have two fields, a foreign key to Exercise, and a field to store how long it took to finish.
Now in Javascript, you're going to time the exercises, and then post them to a Django view that will handle the data storage. How to post them? You could use http://api.jquery.com/jQuery.post/ Create the data string, data = { e1: timingE1, e2: timingE2 } and post it to the view. You can handle the POST parameters in that view, create a ExecutedExercise object (you'll have the time it took for each exercise) and save them.