Python multithreading 🧵

[@BroCodez]

# ****************************************************** # Python threading tutorial # ****************************************************** # thread = a flow of execution. Like a separate order of instructions. # However each thread takes a turn running to achieve concurrency # GIL = (global interpreter lock), # allows only one thread to hold the control of the Python interpreter at any one time # cpu bound = program/task spends most of it's time waiting for internal events (CPU intensive) # use multiprocessing # io bound = program/task spends most of it's time waiting for external events (user input, web scraping) # use multithreading import threading import time def eat_breakfast(): time.sleep(3) print("You eat breakfast") def drink_coffee(): time.sleep(4) print("You drank coffee") def study(): time.sleep(5) print("You finish studying") x = threading.Thread(target=eat_breakfast, args=()) x.start() y = threading.Thread(target=drink_coffee, args=()) y.start() z = threading.Thread(target=study, args=()) z.start() x.join() y.join() z.join() print(threading.active_count()) print(threading.enumerate()) print(time.perf_counter()) # ******************************************************

[@blizni3371]

If you have problem with huge amount of time displaying by time.perf_counter() function here you have solve of this problem: We can read in documentation: time.perf_counter() [...] The reference point of the returned value is undefined, so that only the difference between the results of two calls is valid. So to solve it we have to declare variable before our code, for example: starting_point = time.perf_counter() ... our code here ... print (time.perf_counter() - starting_point)

[@KudoShinichii1412]

thank you I understood that , but I am really wondering why did not happen to him

[@Mildic]

wow man thank you very much, i was looking at my code for like 10 minutes and couldnt figure it out

[@NoPo1nt]

came here just for this. thank you

[@lukaskelber]

@@KudoShinichii1412 Same, does anyone know why Bro didn't have to subtract two perf counters? Is there maybe some setting for this?

[@Dmitopur]

Thx! I think without your solution that function counted seconds from the point of my pc was turned on.

[@AmmarAlIessa]

Really like how you go to the heart of the subject.. Concise and clear... Thanks..

[@thepragmatic6383]

Thank you for these clear and precise explanations. As I am new to Python, this becomes very practical for my learning.

[@d1jn]

I really like how you explain everything so simply and quickly. Keep it up man !

[@kyokokirigiri166]

I second that!

[@waynefrannedavis9305]

Interesting to see how Python addresses multi-processing and synchronization when compared to Elixir which is my go to language. At 75 years old, I am finally looking at object-orientation.

[@ilyassbabkhouti]

This is brilliant . Excellent explanation !!! 👏👏👏

[@infinitecrafterYT]

nice video bro

[@entity5678]

Such a wonderful explanation..

[@lawrencedoliveiro9104]

For I/O bound problems, it is better to use asyncio than threads. This gives less opportunity for race conditions and their consequent hard-to-reproduce bugs.

[@piotrkopcewicz5227]

dobrze rozkminione :) Dziekowa

[@SleepyAizawa69]

Firstly thank you bro Secondly if you guys have problem with main thread not printing 4then you must delete the() for writting the function in x=threading.thread()

[@baldwin9207]

i was wondering why mine was different. thx!

[@autoauto2000]

@@baldwin9207but why, now it works

[@samuellopez5155]

great explanation, loved the theory before the actual code

[@ilhamm1915]

THAT IS ACTUALLY REALLY COOL NGL

[@ugurbayrak9869]

>>> Very consistent explanation :) >>> Could you please do this kind of tuts regarding python standart libr modules like Struct, OS, SubProcess and Select ? >>> Have a good time

[@VenkataChalaBhaskar]

Excellent Explanation !!!

[@ilordepic]

hope the algorithm blesses your channel

[@felixnyamongo]

Understood in one go. Good work bro

[@FabioRBelotto]

I would like that you showed an example like this : you can eat and drink at same time, but you must finish such activities to study.

[@shuaibalghazali3405]

Thanks for this

[@giaxlab]

Super, finally i learn this argument! :) Nice work!!!

[@lw9954]

TY bro

[@bekturasanbekov1979]

thx 4 vid br o!

[@Johann.Liebert]

so simply, thankss

[@aliforootani9348]

great explanation, thanks

[@Sstevewong36]

great

[@rubenc4696]

thakns

[@brianwake100]

Great video thanks

[@gamerawesome8105]

you sir are the best

[@aaroncatolico7550]

Even though you sound like 'Butthead' from 'Beavis & Butthead', I still love you 'Bro'. And thanks for your awesome tutorials. 👍🏻👍🏻

[@kamlesht.j9366]

brooo you da bestt!!

[@EissaAlahdul]

شكرا جزيلا

[@BaminIce]

Print("Amazing")

[@dolevdo]

amazing thank!s

[@HussainAli-sb1dv]

love u

[@nirutg5130]

Thank you very much

[@beingzero7541]

Wow!!!!!

[@ahiamatagabriel5696]

thank youuu

[@Daniel-cl6hj]

breh.... this is so clear...

[@philtoa334]

Nice.

[@SuperStarEevee]

Thank you!

[@charan2446]

Bro.. 👏 Heads down.

[@Amir_Plays_non_stop]

Crystal Clear!

[@xcorpionxyed2078]

Hey bro I've a problem. Whenever I write my own code (following the same procedure) it shows only 1 thread and takes allotted time, but when I copy the given description code it and paste it, shows the 4 threads Can't figure out why is it happening??

[@airexpertdrop]

oh yea its cool

[@RenovaLabs]

Bro, Do they only work with functions?

[@uuhju7004]

nice

[@moisesherrera71]

but what if a function returns a value, how should we write that so we have the function in a separate thread then main but we can capture the return value of the function

[@gustavoaponte1814]

meow~! uwu

[@Pjnpm]

Make a tutorial for flutter please beer is on me 🍺

[@ClydeKilgore-df8hy]

Why do I get the following error after importing threading and attempting to use it? AttributeError: partially initialized module 'threading' has no attribute 'Thread' (most likely due to a circular import) same message when I use active_count()

[@ClydeKilgore-df8hy]

nevermind. figured it out.

[@manuelvaal1257]

My main tread is taking 734078.1110504 seconds to complete its task. what possibly could be the issue?

[@hinter9907]

the solution: # add this line just before running x.start() start_time = time.perf_counter() # add these lines after z.join end_time = time.perf_counter() delta_time = end_time - start_time print(delta_time)

[@cinquecento1985]

yeah.. multi threading in the morning.. sounds familiar. like brushing teeth while getting the pants on.. =)

[@autoauto2000]

does not work 4 me?? how to unlock gil in pycharm

[@estudio7753]

ate

[@aiviral_]

Hey I got this problem with Python showing 34568.4580 seconds while it only takes 3-4 seconds and it's not the only case in which this happens. Does anyone know how to display seconds correcty?

[@wilsonsoeparman8574]

Yup, me too

[@mittlope2723]

just divide it with 10,000 and you will get 3.4 secs

[@mm-fn9uj]

somewhy i have 374690.9 seconds

[@hinter9907]

the solution: # add this line just before running x.start() start_time = time.perf_counter() # add these lines after z.join end_time = time.perf_counter() delta_time = end_time - start_time print(delta_time)

[@techboomers8935]

Kindly revealed your face , we want to sees a person who know every language exist in this world

[@reinkdesigns]

should i be concerned that when i run the same code as you i get "590447.4203372" returned from "print(time.perf_counter())"

[@ramanuj_g]

check above comments as the answer is there above.... nothing to be concerned just u have to add start time and subtract it from end time

[@peesnlav]

for some reason my main thread waits for the other 3 threads to finish before it executes the print functions. i wrote the exact same code he wrote. anyone have an idea?

[@blizni3371]

Hello, you probably wrote parentheses when declaring - target= for example: x = threading.Thread(target=eat_breakfast(), args=()) Remove this and let's check again :)

[@stevemiller123]

I have the exact same issue, did you resolve it? Even when copying and pasting the code from the description. It's behaving as if I joined all the threads even when I haven't. So when I actually write, x.join(), y.join(), z,join().. the behaver is the same.

[@MrPsichoKid]

@@blizni3371 jesus Christ, thanks man, i was in a hole for like 2 hourse before figuring out this!

[@blizni3371]

@@MrPsichoKid No problem!

[@ligdjumvidja8294]

Thanks a lot my friend ! Iwas trying to figure out why my example was faulty @@blizni3371

[@ixmjk]

Thank you Bro i run the exact same code but for me the time.perf_counter() returns a really big value for time taken sth like 11929.1326382 but in reality it takes 5 to 6 seconds to run i search online for solutions but nothing came out. Any solutions?

[@aiviral_]

I got the same issue :\

[@wilsonsoeparman8574]

Me too

[@lawrencedoliveiro9104]

Are you taking the difference between values? Because the zero point is implementation-defined.

[@nakiros24]

this worked for me: import threading import time def eat_breakfast(): time.sleep(3) print("You eat breakfast") def drink_coffee(): time.sleep(4) print("You drank coffee") def study(): time.sleep(5) print("You finish studying") begin_time = time.perf_counter() x = threading.Thread(target=eat_breakfast, args=()) x.start() y = threading.Thread(target=drink_coffee, args=()) y.start() z = threading.Thread(target=study, args=()) z.start() x.join() y.join() z.join() print(threading.active_count()) print(threading.enumerate()) print(time.perf_counter()-begin_time)