Saturday megathread: Share your resources!

Found a neat resource related to Python over the past week? Looking for a resource to explain a certain topic?

Use this thread to chat about and share Python resources!

/r/Python
https://redd.it/imr8h6

Discrepancy in logging output between IDLE and Terminal

import flask

app = flask.Flask(__name__)

@app.route("/")
def about():
return hello

if __name__ == "__main__":
app.run(debug=True)

When the code is executed and I visit [http://localhost:5000/](http://localhost:5000/) , I get a NameError exception page from the debugger, which is expected. However, the stderr output in the shell differs:

IDLE

================= RESTART: /Users/eExamSystem/Documents/app.py =================
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
* Restarting with stat

IDLE Without Debugger (For comparison)

================= RESTART: /Users/eExamSystem/Documents/test.py =================
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
[2020-09-05 17:57:38,774] ERROR in app: Exception on / [GET]
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/flask/app.py", line 1982, in wsgi_app
response = self.full_dispatch_request()
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/flask/app.py", line 1614, in full_dispatch_request
rv = self.handle_user_exception(e)


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

I made a Spotify ad stopper because I was too poor for Premium. It automatically detects when an ad plays and then restarts Spotify in the background. It's my first project after escaping tutorial hell and I'd love any feedback you guys have!

It detects when an advertisement plays by monitoring the type of what track is currently playing, using the Spotipy api. It then closes and opens Spotify by the os module and plays it via pynput.

There have been a few programs in this subreddit which offer a similar functionality but mute spotify, and play another locally-stored song. I preferred not using that method and hence did this.

The code is present below, and is also present in my github repo [here](https://github.com/SakDev/SpotiByeBye).

Once again, I truly would appreciate any constructive feedback!

**Edit**: Thank you so much for your positive response!!!! I've added a readme file to help anyone understand the gist of setting up the Spotify API to get your Client ID and secret.

And to all the people who claim this is stealing, I just wanted to say that while it does test ethical bounds, this program merely restarts Spotify using legally-obtained data from Spotify. Chill dude.

​

https://preview.redd.it/prkuja5q6cl51.png?width=4560&format=png&auto=webp&s=36f824adc24665e71d497aeb7e8afde5b1f2e9f7

/r/Python
https://redd.it/in1pyu

What are the uses of vue.js and react with django ? How they are useful in django ?

Right now i am learning django. I know basics about python. I see many tutorials about django+react and django+vue.js for making webapps but I want know when to use vue.js or react with django.

/r/django
https://redd.it/in3jvb

Sunday megathread: 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/inbwja

I wrote a mass emailing script named MassEmailer that you can input any sized text file of email addresses and an email body text file and it will mass send out the email. You can schedule it to send a set amount of emails per day to stay within provider limits until it has been sent to all emails.

[https://github.com/trevtravtrev/MassEmailer](https://github.com/trevtravtrev/MassEmailer)

The readme contains all the instructions you should need to run it. The code has docstrings explaining each function. It works perfect but would like to hear feedback for how it can be written to be more user friendly. Please feel free to critique here or use the code in any way you'd like. Please make sure to follow the readme to get the script running for yourself.

I currently have a 5,000 email address text file and 1 text file with the email body text. I have it set to send 100 emails per day via gmail (this is gmail's limits) and it is set to run once every 24 hours with windows task scheduler. It deletes email addresses from the text file as it sends to them so it can run seamlessly the next scheduled time picking up where it left off. Keep a backup copy of your email list elsewhere.

If this is popular, I will add updates and maybe even make an interface.

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

How to have encrypted chat between users, where the site owner cant read any of the messages?

* The messages would be stored in the database
* Im guessing this will deal with hashing
* The site owner should not be able to read any of the messages
* Users will be private messaging other users
* Is there any common lib/tool/package that can be used with Django to accomplish this?

/r/django
https://redd.it/ing5h4

testing in django

Hey, does anyone knows some good django testing examples to learn from?

/r/django
https://redd.it/in975x

I used Python, Flask, HTML, JS, CSS, and Google Colab to create a web-app. How would I deploy this permanently rather than temporarily?



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

PyCon India 2020

Ticket sales for PyConIndia2020 are open.

Rush to get your ticket: [https://in.pycon.org/2020/#ticket](https://in.pycon.org/2020/#ticket)

PyCon India is the annual gathering of Pythonistas, run by the Indian Python community, to foster adoption of the Python programming language.

With over 250+ proposals coming in globally, job board, workshops, dev sprints, and networking opportunities. This year PyCon India 2020 is set to be the biggest one yet.

We will be having a job board where you can find exciting job openings from various companies that uses Python and related technologies in various domains like web, infra, security, embedded, or data science.

No matter if you are a student, someone who is just starting out with Python, a seasoned programmer, or looking for your first programming gig there is something for all.

To make the event inclusive and accessible to all, we have kept the ticket prices to a bare minimum of 199 INR, or roughly 2.68 USD.

https://preview.redd.it/9soen7u2vhl51.jpg?width=1280&format=pjpg&auto=webp&s=376ef25646c4bfbede310d60d14ab35091eb5225

/r/flask
https://redd.it/inj0pu

[P] YLYL but I made an AI that turns off my PC if I laugh
https://youtu.be/glQlfFsVg-k

/r/MachineLearning
https://redd.it/ini1r5

Ultimate Python study guide

[https://github.com/huangsam/ultimate-python](https://github.com/huangsam/ultimate-python)

Ultimate Python study guide for newcomers and professionals alike. 🐍 🐍 🐍

print("Ultimate Python study guide")

I created a GitHub repo to share what I've learned about [core Python](https://www.python.org/) over the past 5+ years of using it as a college graduate, an employee at large-scale companies and an open-source contributor of repositories like [Celery](https://github.com/celery/celery) and [Full Stack Python](https://github.com/mattmakai/fullstackpython.com). I look forward to seeing more people learn Python and pursue their passions through it. 🎓

Here are the primary goals of creating this guide:

🏆 **Serve as a resource** for Python newcomers who prefer to learn hands-on. This repository has a collection of standalone modules which can be run in an IDE like [PyCharm](https://www.jetbrains.com/pycharm/) and in the browser like [Repl.it](https://repl.it/languages/python3). Even a plain old terminal will work with the examples. Most lines have carefully crafted comments which guide a reader through what the programs are doing step-by-step. Users are encouraged to modify source code anywhere as long as the mainroutines are not deleted and [run successfully](https://github.com/huangsam/ultimate-python/blob/master/runner.py) after each change.

🏆 **Serve as a pure guide** for those who want to revisit core Python concepts. Only [builtin libraries](https://docs.python.org/3/library/) are leveraged so that these concepts can be conveyed without the overhead of domain-specific concepts.

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

When to use Classes and when to use Functions in Django

The title says it all. I'm a little confused about when to use Classes or Functions in [Views.py](https://Views.py) on Django.

/r/djangolearning
https://redd.it/inkg7v

Keep a <div> scrolled all the way to the bottom as new input is appeneded.

Hey all! Question is pretty simple; I have a div that is dynamically extended as the user sends input. Everything is working quite nicely, except that every time the user submits a new request, the div pops all the way back up to the top. I would prefer that the div always stay scrolled at the bottom unless the user scrolls up with their mouse.
Basically I want to do what the user in [this question](https://stackoverflow.com/questions/15688656/how-to-keep-a-div-scrolled-to-the-bottom-as-html-content-is-appended-to-it-via-j) has already accomplished (not what they are asking in this SO post). However they are using JavaScript and obviously I am using Flask. Is there an easy way to do this using Flask? If not, is there another way this may be accomplished?


Any help would be much appreciated!

/r/flask
https://redd.it/inrju5

Why Python list comprehensions are faster and more elegant

Hello! Since my last disassemble-ing video was so well received, I made another one!

In this video we disassemble list comprehensions and find out why they are faster than their for loop cousins: [https://www.youtube.com/watch?v=kp0QWQbSv30](https://www.youtube.com/watch?v=kp0QWQbSv30)

If you are not familiar with Python bytecode, feel free to check this other video out before which explains it: [https://www.youtube.com/watch?v=HY7cMB0Rx8w](https://www.youtube.com/watch?v=HY7cMB0Rx8w)

I would love to see a discussion on if you've ever heard of python bytecode, and if you have, how you have used it to improve your understanding of the Python interpreter!

/r/Python
https://redd.it/inmda0

Monday megathread: Project ideas!

Comment any project ideas beginner or advanced in this thread for others to give a try! If you complete one make sure to reply to the comment with how you found it and attach some source code!

/r/Python
https://redd.it/inwyn1

My Django app passes authentication on localhost, but not on heroku

So I created a simple "social media website" where by using API I GET data from a database and I can also POST to create a social media post after I register and log in. On my localhost it all works well. I can register, login, then write a social media post and it displays on the screen. However, when I use Heroku, GET API works fine, but after I log in (and I am sure I am logged in as I can log in on admin), I cannot write anything on my website. In my IDE I get: Forbidden: /api/posts/action/

In the network page I can see this:

Request URL: http://localhost:8000/api/posts/action/ Request Method: POST Status Code: 403 Forbidden Remote Address: 127.0.0.1:8000 Referrer Policy: no-referrer-when-downgrade

Any idea where should I look for an error? If there is any code I should send, let me know. Thank you!

/r/django
https://redd.it/io0jc7

Tesla V100 GPUs are now available in Colab! [Discussion]

&#x200B;

https://preview.redd.it/gs55dli7ynl51.png?width=712&format=png&auto=webp&s=2cf12b68096df12d08ac4d71a55acb4872f8b921

/r/MachineLearning
https://redd.it/io201w

I created a coronavirus dashboard using Dash from Plotly making predictions for all countries and US states

I created a [coronavirus dashboard showing all COVID-19 deaths/cases][1] for all countries and US states along with predictions for all those areas.

I also created a [page to view model performance][2] for all areas at any historical date.

The model is built by first using repeated moving average smoothing and then a combination of exponential and logistic growth functions with growth rate modeled as a function of time.

Libraries used:

* pandas to read in and clean the data
* scipy to fit function parameters
* plotly to make visualizations
* dash to build web application

[1]: https://coronavirus.dunderdata.com
[2]: https://coronavirus.dunderdata.com/model_performance

/r/Python
https://redd.it/io9650

[D] PSA: NVIDIA's Tensor-TFLOPS values for their newest GPUs include sparsity

NVIDIA claims the 3080 has 238 ‘Tensor-TFLOPS’ of performance from their tensor cores, the 3090 has 285, and the 3070 has 163. As usual, these numbers are for 16-bit floating point. In contrast, the 2080 Ti has only 114 TFLOPS of ‘Tensor-TFLOPS’, so you would be forgiven for thinking the 30 series will be much faster at training.

Alas, the values for the 30 series are *TFLOPS-equivalent with sparsity*, not actual TFLOPS. Ampere has support for ‘2:4 structured sparsity’, which accelerates matrix multiplications where half of the values in every block of four are zeroed. This means that the actual number of TFLOPS for the 3080, 3090 and 3070 are 119, 143, and 81.

When Ampere originally launched on the A100, NVIDIA was [very clear](https://www.nvidia.com/en-gb/data-center/a100/#specifications) about differentiating real TFLOPS from TFLOPS-equivalent with sparsity. It is incredibly disappointing that NVIDIA have been not at all upfront about this with their new GeForce GPUs. This is made worse by the fact that the tensor cores have been cut in half in the GeForce line relative to the A100, so it is easy to get confused into thinking the doubled numbers are correct.

Although hardware sparsity support is a great feature, it obviously only provides benefits

/r/MachineLearning
https://redd.it/ioa9za

Python Tips and Best Practices for Building Robust Data Science Workflows
https://medium.com/swlh/software-engineering-tips-and-best-practices-for-data-science-5d85dbcf87fd

/r/Python
https://redd.it/io4rx5