Asyncio - Asynchronous programming with coroutines - Intermediate Python Programming p.26

[@JohnDoe-vr4et]

I didn't know Edward Snowden was now doing Python tutorials.

[@Cal97g]

I actually thought this about this guy when I first saw him a few years ago haha

[@michaelwilson8461]

Honestly, when I first started this series I couldn't help thinking he needed an "evil" white lab coat and old fashioned dark welding goggles sitting on his head. Thought I was watching Dr Horribles' Python blog for a second. Guess we know what would happen if Neil Patrick Harris(on) and that oldest kid from malcom in the middle had offspring lol

[@thengakola6217]

u should've known

[@GoonCity777]

I thought the lead singer of Semisonic

[@shayneloyd]

Shh, if they catch on they will stop sending him the KZbin money.

[@bradm8128]

love learning python from Mr. Snowden

[@vidura23]

I just completed your tutorial set during the lockdown and I just want to say a massive THANK YOU for your tutorials. I'm a mechanical stress engineer and I always wished that I knew coding to automate and write programmes to help with my work. I now have a good basic understanding of Python thanks to you and several other KZbinrs. I even managed to build few robots. Keep doing what you are doing!

[@smartmineofficial]

Asyncio sounds like 'Ay, se cayó!' in Spanish, which translates to 'Oh no, he fell down!'

[@MrTeddybearGame]

Probably the guy that tried tying his shoe while running...

[@shreyashkashyap]

This was the best explanation of Coroutines on KZbin that I found.

[@damianshaw8456]

Very helpful, I'd just got my head around starting to write Python async code and this was great. FYI I believe it's standard practice to do "await asyncio.sleep(0)" not "await asyncio.sleep(0.00001)". The 0 is enough to interrupt the task and give the loop/interpreter a chance to switch to something else and it saves having to create a real timer which I think can have small performance hits.

[@sentdex]

You are absolutely right about the sleep(0) being the paradigm, thank you for the clarification

[@nano7586]

7:05 AMEN. Documentations just need to have a short introduction with a simple example so people at least know what they're dealing with. I don't understand how this isn't a thing.. seriously. People would have so much more general knowledge with such easy things (applies to Wikipedia, university, tutorials, literature, etc.)

[@vapon]

Coroutine stands for concurrent routine. When a function is to be split in pieces (async), then await should be called somewhere in that function and it's where the function (the flow) is going to be split (interrupt). Those interruptions and callbacks must be co-ordinated by someone: that's the event loop! A fifo queue where jobs are scheduled. So the reason of an await asynchio.sleep() is to give the function a chance to be split and the event loop a chance to check its queue of what else has to start or resume ;)

[@_test_test]

for a long time i was ur subscriber but about a half a year im starting programming myself. ure doing awesome lessons, coz u show it in easy way. thx budd.

[@williamli55]

I was waiting forever for you to address the fact that the entire function is CPU bound. I was about to throw a tantrum in the comments. Glad I waited😁

[@tylerhuang6701]

Great video! I have a question about the output at 20:12. If I understand it correctly, divs2's task finishes before divs3's task because in divs2's task, i never reaches 500,000 so it never hits sleep(). So then I was wondering why it prints out "finding sums in range 500 divisible by 3" before printing out "Done w/ nums in range 100052 divisible by 3210" because shouldn't divs2's task finish before div3's task starts as it was never put to sleep?

[@bratwurst6666]

I enjoyed that he was hanging on the if-statement. It is just more realistic that shit like this goes wrong.

[@cluberic]

At 11:40, can you explain how you are using the variable "loop" in main(), when it was declared in if __name__ == '__main__':?? Are variables instantiated in that usable in the whole class?

[@pisoiorfan]

if i % 50000 is TRUE 49999 times, that's why it got so slow

[@aslan1504]

Well, it depends on i var)

[@berndo3038]

Actually, even more than that in his example. Because it would be truthy for anything that's NOT divisible by 50,000. Which if you're iterating through every number from 0 to 508,000 would happen 507,990 times.

[@sudiptapandit7640]

What a coincidence! I just about to search other sources for this topic... but now i can get it from my favorite source .😘

[@mitchellfolbe8729]

Thank you for all of these videos. Lots of fun going through them all. Appreciate the hard work.

[@abuslume4169]

Besides that bug where you forgot the == 0 after the modulo statement and i was yelling at my screen, this is the only tutorial i've watched that's been able to help me with wrapping my head around the asyncio library. Thank you!

[@sciencedoneright]

It doesn't even seem useful but it is so useful

[@rivaanb]

Asynckio 😂 this is what I will call it from now on 🙌🏼 great video! Thanks..

[@DivineZeal]

This is the final gem i needed for my python bot, thank you, master Sentdex aka Edward

[@carolchen4753]

Very helpful. Thanks Edward!

[@teddycristian2779]

thank you for the intro, you made it clear with the running example.

[@MelarDev]

12:40 Yes, there are examples when you use async without await, anything you do over an unreliable protocol such as udp, for example send logs to a server or streaming media may be done asynchronously and you never want to know anything, you even skip errors so you never do await.

[@edwardwilliamsams6589]

thanks for all the hard work Sentdex.

[@77shoemanable]

Best explanation ever !!

[@FuZZbaLLbee]

Have had good experiences with await in c#, so will also try it out in Python

[@tankman6452]

I try it again and again, the sample code just doesn't work, the amount time is always same whether use asyncio or not.

[@tankman6452]

Oh, I know why! First time you finished in 32.6s because range number is 50800000, and second time you finish in 0.4s, it's not because you use asyncio, you just modify range number to 508000 and edit the video. You think all users are idiots? no idea where these good comments come from. full of bullshit

[@dan400919]

@@tankman6452 it is not about accelerate execution of div1, it is about to not wait till prev instruction is executed. it doesn;t matter if you put 50800000 or 508000, in both you have to wait till div1 is executed which it takes almost 30 sec , so you are somehow blocked by div1 to have result for div2. using async you get div2 results till div1 is processed. He did a presentation mistake , though.

[@muhammadtalhabaig4908]

Thanks a lot for this series man! Really enjoyed and learned a lot from you. I hope you will be making more tutorials like these in the future. My favourite part in this series was the blob game project. Keep it up 😃

[@taxi_boast]

Thank you for taking the time to make this video. I must say though that the tying the shoelace example wasn't the most intuitive or appropriate. There are better examples to use.

[@i701Dev]

Thank you for this tutorial.

[@tuhinmukherjee8141]

Hey good work Harrison, but for people who are really interested in going into the details, you might wanna check out EdgeDB's "import asyncio" series which is by far the best asyncio series I've ever seen. Asyncio is TOO huge to be covered in a single 30 minutes video !

[@el3ctron]

thanks for sharing NSA secrets and doing this python tutorials

[@sentdex]

My pleasure!

[@PlasmoX]

when running async on a function, does that mean i need to make all other functions run async? or just what i want to run together?

[@Scratchmex]

You can use asynio.sleep(0) to just gives back control and not have time penalty for each change

[@keklol1408]

Actually, it would be much more productive to take the "div_by" and multiple it by following integers until the result it is less than "inrange". Thank you for your tutorials, they are great. I understand that this function is just for a sake of example.

[@samapriya1]

Is it possible to show an example with an asyncio downloder downloading maybe from a list or urls? Would love to have that application built using async instread of multiprocessing

[@oliverwann3300]

Thanks a lot for your giving. I am a 'asyncio' beginner. AND I think ..emm... I should spend some time to learn it .

[@JusticeNDOU]

you cannot DOS someone if you do not await, because once you do not await you probably never even had a coroutine or you have a coroutine but its not sent to the event loop, the effect in eiher way is that you end up with an awaitable which is never executed

[@uppubhai]

Much needed video, Thanks a lot sir

[@josephs3973]

Just starting out with Python. How come the loop object is in scope in main()? Is it magically passed by run_until_complete() or something like that? Ugh.

[@gesuchter]

It's been a long time since the last video in this series :o I love them, please post them more often!:)

[@sentdex]

any requests for fitting topics to this one?

[@max2070]

maybe new Django/Flask or AI project will be good?

[@lucagorzog2490]

sentdex dataclasses ? type notation?

[@randiaz95]

I think one thing I would really like to learn is encrypting in python.

[@Boxylon]

@@sentdex hashing and hash tables

[@MElixirDNB]

how is loop defined in main? Is there some magic happening in asyncio that makes the loop variable available because you call loop.run_until_complete ?

[@fastrunner8494]

Man i learned you are very happy.

[@kunomels]

Very nice video thank you :) (Some sound engineer advice : put a high-pass filter at about 100Hz on your mic feed. It makes it more confortable to listen by eliminating low freq shocks)

[@J2000Ray]

Could someone tell me how the references to that loop object in his main function are valid? That loop object shouldnt be in scope of that main function, right?

[@rifatmasud]

You're just one happy programmer 😀

[@EnglishRain]

Amazing video! Thank you so much Ed!

[@Rostgnom]

Why isn't `loop` undefined in main()?

[@ZenMasterScr3wy]

Loop is defined before main() is called. loop = asyncio.get_event_loop() loop.run_until_complete(main())

[@Rostgnom]

Oh, right, now I see it. That's why you should follow programming practices tbh ^^

[@soundwaves1752]

probably I don't understand concurrency, but your first example was a cpu bound task. why should you use asyncio on that. why should the task give control back to the loop when it is cpu bound. i think multiprocessing would do better for that and not asyncio.

[@rammanoj6110]

hey, thanks for the tutorial. But I guess using running the same code locally increased the time (instead of decreasing) on adding the condition `if i % 5000 == 0: await asyncio.sleep(0.0001)`. The one thing I don't understand is even if you perform blocking, it just stops the current loop and executes another. However, it has to perform all the computations. So, you are not blocking the coroutine while it is waiting, you are doing while the computation is equal to some number. So it need to perform the computation again once it resumes. Hence I don't find the need of above if statement?

[@yugandharchaudhari1376]

should a caller f2 of async function f1 should necessarily async?

[@sundaresann4749]

Please make a video on how you make your videos , I mean how do you learn , practice, take notes to teach ?? Will you be using any tools I'm sure u do . What is it? How do actually you manage time BY making THIS MUCH OF VALUEABLE CONTENTS ?? im curious as well as confused. Shd I ve to take teaching notes while learning or during practice . If you have time please make a video. Will be useful for many. Thank you a lot.

[@prhmma]

can anyone please tell me the name of this theme?

[@vuminhquanle1426]

10:20 LoL, I laughed so hard when you try to negotiate with the language about how it should be

[@mpete0273]

Is there a reason to use asyncio over Threading or Process for simple tasks?

[@sahilbali4953]

For scaling asyncio is awesome, just that.

[@sparttann1312]

I'm working in Spyder(+ Ubuntu) and get RuntimeWarning: coroutine 'main' was never awaited with final script from pythonprogramming page. Any idea?

[@raghav4296]

Came here after your Go routines tutorial. Thanks for all the explanations and knowledge. Appreciate it. Asyncio is not supported in Flask and I guess Django has limited support. Rest async libraries like Sanic /aiohttp has limited to no cloud API examples. As a python backend person working on any of the public clouds, how would one send async requests as easy as we do in NodeJS..? Thank you.

[@wuda-io]

When you like sublime... then try vscode i went from idle to sublime to vscode its awesome :D

[@ego_sum_liberi]

Yes, vscode is top!

[@Alex4n3r]

It's very scary that the new IDEs are built in html and therefore are vulnerable to html injection (even as comments) when you run downloaded code.

[@ChEkOv]

I was in notepad++, then vscode then sublime.. now I recommend atom! community first.

[@VictorRodriguez-zp2do]

Vim is always better

[@vapon]

sublime is c++ and python

[@nikhilnambiar7160]

Can we use async to read more than 10k files and perform operation over it ?

[@punyamaremalla2444]

what is add_done_callback ?

[@Indemere]

Yo sentdex, you should do a tutorial on Apache Spark, from processing huge data sets! Would be very interesting to see your take on it. Cheers man, love the videos!

[@Astral96]

@2:10 "and waiting on a response" * starts drinking * and we be waiting hahaha

[@PoiSonSonic]

Does anybody see a sound/video delay or is it just new chrome?

[@sentdex]

Probably a delay.

[@PoiSonSonic]

Apologies, it's my bad. It is misbehaving only on Win10, android YTplayer is playing out fine. #Hate WSAPI 10outof10

[@NagarajCruze]

How can we use this program without making it to sleep?

[@DarkRedman31]

I like the video, but still after I watched it, I don't get the point of asyncio in this example, and sync coroutines can already be done using generators (cf works and examples done by David Beazley aka Dabeaz), why asyncio ?

[@spacecapitalism7152]

Would you say learning Asyncio in python is dumb because Go is the way to go?

[@sentdex]

Go is not a mature language like Python is. IMO, Python is still the way to go. Go has a ton of potential, but a long way to go.

[@jeremiahbill5374]

which sublime plugins are you using?

[@sentdex]

It's just called "sublime linter." Been using it to force myself into pep 8. Trying to get some better standards as habit.

[@jeremiahbill5374]

for sure, i can definitely attest to that! btw, love your videos have been a fan for a while! the machine learning series is one of my favorites and one i frequently come back to!

[@adriantarver2229]

Hey sentdex, have you ever thought about covering the cryptography module for python 3.6? I was wondering if you could possibly cover it at some point?

[@omarsalama6312]

can you add to GtA5 play the v6 to tutorial with data and code ? or add it on github

[@franzweitkamp]

Is there a reason why you use "... {}...{}...".format(x,y) and not f"... {x}...{y}..."? The second is so much easier to read.

[@cizbarca]

Franz W backwards compatibility

[@paddym27]

great video, thanks!

[@Vinomix]

Quick question why did you pick sublime text over the other editors. Please Answer ..!!!! Thanks

[@IsItTimeToTravel]

Great job. A question. Where can we use this ? If I have a web page with many objects that I am refreshing every minute (assume), can I use asyncio to achieve independent updating without reloading?

[@chuckynorris616]

much easier to run parallel functions using the gather method instead of hacking with sleep and awaits loop.run_until_complete(asyncio.gather( find_divisibles(508000, 34113), find_divisibles(100052, 3210), find_divisibles(500, 3), ))

[@somethingcoolgoeshere]

"unless your trying too dos somebody" lol good example

[@psg8177]

What was that sublime package that gave you floating errors like in the pycharm ????

[@songokussj4cz]

So... I have to always add *yield from asyncio.sleep(0.0000001)* (python < 3.5) or *await asyncio.sleep(0.000001)* (python >= 3.5) inside the function for it to work?

[@sentdex]

You just need to await something. You might await a response object, for example.

[@simplepycodes]

hi im getting error: loop = asyncio.get_event_loop() AttributeError: module 'asyncio' has no attribute 'get_event_loop' did package changed or its a bout python version?

[@unshakeabletraderph6971]

The best way to visualize async is when Jackie Chan fights multiple opponents. 🤣😂

[@tomaszsosinski5935]

Hi! I liked the video a lot! Great work! I only wanted to point out that concurrency and asynchronous computations are two different things and it is a bit dangerous to use them interchangebly.

[@nektoxyz1013]

Hi. Maybe i'm wrong, but.. should i explicitly set await.sleep(n) period?? n goes to infinite lower, i suppose. or.. await asyncio.sleep(0) expression for returning CPU timing for another coroutine. another coroutine takes CPU time intil it stops execution, or meets same expression. or I got that logic wrong?? P.S. Thanks for tutorial on asyncio. I;ve spent a lot of time trying my code run asynchronosly)) But till now i'm not sure if it is runs so... Waiting for another video about asyncio, aiohttp, or websockets pytohn lib (they are written in async), or anything with async. For me it looks like async Magic))

[@lostlewis7577]

Have you heard of, or use, uvloop in unison with asyncio to replace event loops? Went snooping around and it seems like it might be a good drop in library. Thoughts anyone?

[@marcelnitan]

Is there any difference between using create_task(func()) and await func() ? Like I'm used of doing async def main(): var1 = await func() instead of async def main(): var1 = loop.create_task(func()) await asyncio.wait(var1)

[@bottlerider8898]

If asyncio.get_event_loop() fails for some reason, you'll try to execute a method of a non-existent object in the finally section.

[@raghavgupta1157]

Is it outdated? Do we have "await" keyword now? Or this library still needed?

[@etcetc3800]

how much did you pay for that crypto graphic?

[@enriquematos6461]

hi man, great video but I have struggled a lot installing the package asyncio... do you have any guide? the usual pip does not work

[@ChEkOv]

Please describe diff between asyncio vs multiprocessing with some example pls. thanks!

[@sentdex]

multiprocessing can still be highly wasteful with latency and i/o times. You might be able to get jobs done in similar times, its just the asyncio will do it more efficiently in terms of hardware used. That said, you can combine the two, and ideally would. They just aim to solve different problems. Multiprocessing just helps you fully utilize the hardware that's available to you. Asyncio helps you fully utilize your time. Hope that helps.

[@ChEkOv]

Excellent. As we're getting used to :)

[@padraic1983]

Damn SentDex.. just saw you broke 1 million!

[@akashdeepjassal3746]

I have a question can one use asyncio with scikit-learn or pandas ?

[@sentdex]

Yes, but you didnt provide much information. There are many ways you could use asyncio with them, and many things that you either cant or asyncio wouldn't help you with in regards to those packages.

[@akashdeepjassal3746]

Would love to see if you explore that.

[@eric321ification]

Some data libraries have built in async and threading helpers built in. I feel it is more Pythonic to use those library built ins rather than adding more imports. An example is with PySpark here blog.knoldus.com/2015/10/21/demystifying-asynchronous-actions-in-spark/

[@wilfreddv]

I think `run_until_complete` waits for a return value from `main()`. `main()` just creates a couple of tasks and returns `None`, not awaiting the tasks.

[@asifmohammed5436]

16:50, check reminder is 0, otherwise program will stop for 0.00001 * (~100000) seonds

[@geraldoneto123]

Would you recommend using Asyncio for robotics (with Raspberry PI)? Thank you!!

[@MaxTechEngineering]

Neto Carvalho how would you think of applying it?

[@geraldoneto123]

Max Lee basically to operate the entire robotic vehicle. Reading sensors, driving the motors, break, etc.

[@vapon]

Thumb rule is to use threads for CPU bound operations and async for IO bound operations. I love robotics!

[@lostlewis7577]

@@vapon threads as in multiprocess? multithread should be for I/O too

[@vapon]

@@lostlewis7577 threading is way more efficient in a multi-core context

[@pawsdev]

So, after this tutorial i understood, that yet nobody knows how to cook async properly and why it is invented

[@sentdex]

Apparently you realized that about yourself.

[@trykozmaksym]

Good stuff.

[@lodashnotebook5390]

Hey @sentdex! Quick question, can I order the Python Cap? I was wondering what's wrong with the store it is closed :(

[@NaturalBornCamper]

I usually understand everything after Sentdex's videos but this time I'm so lost and confused. I don't understand the role of "await"

[@memestagestartup]

how bout tying shoes while running

[@sentdex]

Possible, but hard, and a lot can go wrong, like falling on your face. In most cases we're better off stopping to tie them.

[@wolfisraging]

Thank u so much sir, just keep doing what you do. Big fan😊

[@europmedia4828]

Thank You!