Save Image in MongoDB with MongoEngine

Currently I am learning the mongoengine and just made the video for saving image files directly in MongoDB , wish you like it.

[https://youtu.be/PO-z4nwdMUs](https://youtu.be/PO-z4nwdMUs)

MongoEngine works very well with flask and mongodb! If you have any suggestion and questions, please leave the comment. I am very happy to know all of you. :)

/r/flask
https://redd.it/b88o0u

How can I pass data between SelectMultipleFields?

**[UPDATE]**

After banging my head against this all weekend, I finally found the answer. The problem is that the default validators in `SelectMultipleField` don't actually work. If I replace `validate_on_submit` with `is_submitted`, the code runs. This version does what I want it to:
```
@streams_blueprint.route('/select', methods=['GET','POST'])
def select():
# Grab a selectable list of studies from database.
form = SelForm()
db_objects = [(stream.id, stream.name) for stream in Stream.objects()]
form.selections.choices = db_objects
if form.is_submitted():
form2 = SelForm()
selections = form.selections.data
new_objects = [(stream.id, stream.name) for stream in Stream.objects(id__in=selections)]
form2.selections.choices = new_objects
else:
form2 = SelForm()
return render_template('select_streams.html', form=form, form2=form2)
```
If I need validators, I will have to write custom ones for this field type.

**[ORIGINAL]**

I'm new to Flask and WTForms, and have been really struggling with this simple task. I want to display a list of options. The user can select multiple options, and then these choices generate a new

/r/flask
https://redd.it/b7gnhg

RPI 3 B+ Virtual ENV

I know what a VENV is and how it works but i dont get how i link my python script to the Env. Anybody who can explain?

/r/Python
https://redd.it/b8gwk3

Dynamic Dashboard stats with Flask, Redis and Postgres

I have an admin application that has a dashboard page with various statistics for our company. Basically our data is stored in Redis, and right now still thinking of a way to combine Postgres and Redis to work together as both our data store.

​

Any idea how I can update the dashboard dynamically? Say like every 5 minutes or depending on what we set, it doesn't have to be real time.


My thinking is that, I will run a background job that will pre aggregate data on redis and store that on Postgres for record, then when a user refreshes the dashboard or visits the dashboard, it will fetch the latest aggregated data from Postgres. Maybe use AJAX to update the dashboard periodically.

/r/Python
https://redd.it/b8hg7k

Django Signals

I want to create something in such a way that there will be a status(pending and confirmed option) on a user page. But when an admin verifies the documents submitted by the user it changes from pending to confirmed. How do you think I can go about implementing this functionality.

/r/django
https://redd.it/b8hohx

An engine for massive calculation complexities

I implemented this dependency graph [https://github.com/hosseinmoein/DependencyGraph](https://github.com/hosseinmoein/DependencyGraph) to facilitate implementing systems with massive and complex calculations that run in real-time. Examples are alpha and risk models in financial industry or modeling an ecosystem in natural sciences.

I appreciate your feedback and suggestions and would like to hear about how you have solved these kinds of problems.

/r/Python
https://redd.it/b8i8y6

Markdown cells instead of Python comments?

I'm new to Jupyter. I code in Python and am wondering if there is a recommendation when to use Markdown cells and when to use comments in Python.

If I have comments in my Python code then why would I use Markdown cells as the purpose of both is to document what is going on.

Any best practice?

/r/IPython
https://redd.it/b8k98q

Aggregating just the code cells without the markdown cells

Once you have finalized your code and want to save from Jupyter notebook to a tradition python script file is there an easy way to copy / paste the code whilst ignoring the Markdown cells?

/r/IPython
https://redd.it/b8ksyn

Accepting Payments with Stripe, Vue.js, and Flask
https://testdriven.io/blog/accepting-payments-with-stripe-vuejs-and-flask/

/r/flask
https://redd.it/b8ityt

[P] Rock Paper Scissors with Artificial Intelligence

Hi! I've created a Rock-Paper-Scissors game that works with artificial intelligence (AI). The AI can see and detect your hand gestures by front-facing camera. Also it can learn your playing strategy in a smart way. The more you play, It gets harder to win!

This app uses TensorFlow and deep learning technologies in order to detect the hand gestures. Sometimes the gestures may not be properly detected, but this will improve in future versions. You can help me in this process by taking pictures of your hand in different positions and sending them as a zip file to rpsapp@outlook.com .

Please Note:

* To get best results in hand gestures detection, put your device on a flat and steady surface.

* In order for the app to work properly, your device should have decent camera and hardware to run relatively heavy calculations.

I've been working on developing this app for a year, so any feedback from you will be a pleasure for me :)

You can get the app on Google Play: https://play.google.com/store/apps/details?id=cc.ramtin.rps

And you can read more about it on XDA: https://www.xda-developers.com/play-rock-paper-scissors-hand-gestures-against-ai-bot/

/r/MachineLearning
https://redd.it/b8htjt

What's everyone working on this week?

Tell /r/python what you're working on this week! You can be bragging, grousing, sharing your passion, or explaining your pain. Talk about your current project or your pet project; whatever you want to share.


/r/Python
https://redd.it/b8jq2r

I Wrote My First Python Package!

Just thought I'd share this: I've been working on a Python package that makes it easy to obtain and work with data from the USDA's Standard Reference Database for nutrient composition of different foods. I became interested in the USDA's API as it seems to be the standard for high-quality nutrition data -- it's used by many apps and it has data for \~160 different nutrients. My goal is to make the data much more accessible to developers.

Part of the package also has a feature which will tell you if you are meeting the Recommended Daily Amounts of each nutrient, so it could be helpful for nutritionists or people looking to improve their diet.

This is the first Python package I've made and I uploaded it to PyPI so it can be installed with pip. You can find the code here: 

[https://github.com/noahtren/noms](https://github.com/noahtren/noms)

Thanks for checking it out, and please share any advice on how to make it better. :)

/r/Python
https://redd.it/b8ncrx

People with experience in Django: is it possible to make a web application with a server push feature?



It should be like this:

I have a Raspberry Pi, an Arduino nano connected to the raspberry and other Arduino nano that will communicate with the "central" one.

My central Arduino, the one connected to the raspberry, will receive messages from others and pass them forward to the serial port. My app needs to read this info and do something about it. It can just be ignored, stored, do something on the Arduino end or it can trigger a event in the app. This event should be like a window that pop in front of the web page telling what happened.

I'm aware of the existence of the channels library and the celery one, too. Although I'm not anywhere near sure if it can be pulled together.

So... Can it be done with django?

/r/django
https://redd.it/b8nm6b

Kellie Ottoboni Receives Award for Post-Election Auditing Notebook
https://blog.jupyter.org/kellie-ottoboni-receives-award-for-post-election-auditing-notebook-96e7277863d1

/r/IPython
https://redd.it/b8nkmn

Simplifying the API for aggregates in a subquery
https://github.com/martsberger/django-sql-utils

/r/django
https://redd.it/b8lro6

Integrating with Slack in 3 minutes (Python + Flask)
https://youtu.be/aVl-ixd7gL8

/r/flask
https://redd.it/b8nag7

How do I prevent POST request on page refresh?

Hello,

Currently I am working on my webpage that has an "add to cart" feature.

​

Everything add to cart is clicked (post request), my session\['cart'\] is updated to include the new product added (list of items in the cart).

​

But there's a problem.

Lets say you add an item to cart, to session\['cart'\] = \[Banana\], if you then refresh the page the session\['cart'\] will become

session\['cart'\]=\[Banana, Banana\].

​

If you refresh again it'll become session\['cart'\]=\[Banana, Banana, Banana\] etc.

​

Is there a way to prevent a page refresh to send POST requests?

​

Thank you,

/r/flask
https://redd.it/b7ennc

How to create unique field with random content with only letters and case sensitive?

I want create random chars for links, such like imgur urls, for example: "abZXy". How to do it?

/r/djangolearning
https://redd.it/b8twbv

8 Python Modules For Files Handling
https://devarea.com/8-python-modules-for-files-handling/

/r/Python
https://redd.it/b8vqom

I wrote a Python package to do adaptive sampling of functions in parallel [OC]

/r/Python
https://redd.it/b8xk3a

Call for maintainers for Celery's Django integrations

Since we're beginning our efforts to develop Celery 5 all resources are going to be directed to that effort.

Unlike Django, Celery has a very small team which we are looking to expand.

Part of the reason for expansion is because we no longer have the time to maintain the Django integrations properly.

​

If you are interested in maintaining our Django integrations, comment here or message me.

/r/django
https://redd.it/b8yv8z