Python Generators

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  • Опубликовано: 18 мар 2025

Комментарии • 224

  • @biffenb7534
    @biffenb7534 2 года назад +417

    I love the relatively monotone presentation, which helps clarity, with only a few incredibly well placed jokes sprinkled here and there. Keep it up!

    • @Holphana
      @Holphana 2 года назад +9

      Monotone? I hear many inflections.
      I would be offended at the implication towards my accent if I were in the RUclipsrs shoes. 😢

    • @biffenb7534
      @biffenb7534 2 года назад +22

      @@Holphana You’re right, I just didn’t choose my words carefully enough. What I mean is that the presentation is that of a factual text, instead of creating unnecessary clutter through adding emotion or emphasis like so many other RUclipsrs do.

    • @Ptolemarch
      @Ptolemarch 2 года назад +1

      Indeed, these are vastly the best videos on coding I've found.

    • @RoamingAdhocrat
      @RoamingAdhocrat 2 года назад

      What's really missing is a title card with a photo of M with chin in hands looking puzzle, or head-in-hands despairing at some topic that was exhorted in many keynote talks - TDD, say

    • @NewLondonMarshall
      @NewLondonMarshall 9 месяцев назад

      What a wholesome reply :) ​@@biffenb7534

  • @l4luchi123
    @l4luchi123 2 года назад +156

    No matter how experienced you are, in your videos there is always a new small detail you didn't know about. Love it!

    • @georgplaz
      @georgplaz 2 года назад +6

      yes! I thought "oh. I know everything about yielding.."
      and then.. bi-directional?! 🤯

  • @SwissTHX11384EB
    @SwissTHX11384EB 2 года назад +146

    Mate, I have years of Python experience, yet everytime you release a video I am floored by some of the stuff you showcase and I feel like I'm learning about the language for the first time. Stellar job, as always, and your presentation style is excellent for the job.

    • @luiz8755
      @luiz8755 Год назад

      same
      it's a little bit overwhelming lol

  • @adsfwef1331
    @adsfwef1331 2 года назад +47

    Dude, you are a genius. I wonder why your vids aren't getting more views than those other millions of python hacks out there. Keep up the good work.

  • @GlutesEnjoyer
    @GlutesEnjoyer 2 года назад +5

    “Even if a file is gigabytes large you’ll only need enough memory to handle a single line” great point!

  • @dhravya
    @dhravya 2 года назад +52

    Always struggled with generators. Thanks for the amazing explanation!

  • @LettuceAttack176
    @LettuceAttack176 2 года назад +14

    I swear every time I start watching a video on this channel I think “ah here is another thing I already know in python I probably won’t learn anything new this topic is pretty straight forward” and I end the video feeling like I never knew anything about it to begin with 😂😂 keep up the great work

  • @ssholum
    @ssholum 2 года назад +92

    Async (vs threading vs "other kinda-multitasking methods") video would be greatly appreciated. It's not the most useful stuff for your average script or simple program, so I rarely see good explanations of it for any language.

  • @Fikerus2
    @Fikerus2 2 года назад +23

    I write things like "sum(x for x in range(10))" very often and I didn't know that was generator comprehension! I was thinking it was the same as writing "sum([x for x in range(10)])" (with brackets). Thanks a lot for your content!

    • @yazanalhariri3700
      @yazanalhariri3700 2 года назад +1

      Me too!

    • @enkryp
      @enkryp 2 года назад +4

      Why using a comprehension at all? Can't we just do sum(range(10)) ?

    • @MrRyanroberson1
      @MrRyanroberson1 2 года назад +1

      @@enkryp i was just about to mention! yeah range is directly iterable

    • @lawrencedoliveiro9104
      @lawrencedoliveiro9104 2 года назад +1

      That’s the difference between an “iterator” and an “iterable”. An “iterable” has an ‗‗iter‗‗ method, which returns an iterator when it is called. The iterator is what returns the elements of the sequence, until it is exhausted and can’t be called again.
      Because range() is an iterable, you can reuse a single range object to return any number of iterators over that range.

    • @Geza_Molnar_
      @Geza_Molnar_ 2 года назад

      @@lawrencedoliveiro9104 Yeah, your explanation helps me a lot.

  • @Gamecrazy721
    @Gamecrazy721 2 года назад +23

    Very insightful video! One other place I've seen generators used frequently is for API pagination. If, for instance, if you want to get all 100 records from an API, and the API limits your query to 10 records per call, you may not want to wait for all 10 calls. Instead you create a generator that calls the API only when you've completed working with the first page and are ready to move onto the second, etc.

    • @lawrencedoliveiro9104
      @lawrencedoliveiro9104 2 года назад +4

      Database queries is a good example. A very common sequence is
      * Create a cursor object
      * Execute a query on the cursor
      * Iterate over the results returned from the cursor
      * Close the cursor.
      You can wrap all these steps up in a single generator function, which takes the query and lets you iterate over the results in a single step.

  • @mabml
    @mabml 2 года назад +34

    Your async explanation would be much appreciated! :)

  • @ahmadhesham1389
    @ahmadhesham1389 2 года назад +4

    This is why I like your channel: Even when I think I know a topic well, I still expect to find something new in your videos, and I always do. Keep it up!

  • @vincentperrollaz5261
    @vincentperrollaz5261 2 года назад +16

    Outstanding video as always.
    itertools might have deserved a mention since it is very useful with generators.
    The jump from iterator to coroutine was a bit steep and I would personally love an async video

  • @rituchandra6325
    @rituchandra6325 2 года назад +4

    "Where the only limit, is your imagination... and your download speed" - LOL I lost it here

  • @MessLeadingProgramming
    @MessLeadingProgramming 2 года назад +14

    Great video. It was eye opening for me when I learnt about generator comprehension. I realised that I was doing something very inefficient passing list comprehensions to sum and other functions.
    Also worker example is amazing. Never used it this way.

  • @lex_darlog_fun
    @lex_darlog_fun 2 года назад +5

    Just as I was about to suggest a video on async, James announced it himself. 👍🏻
    Can't wait to see this convoluted topic explained in mCoding simple comprehensible manner.

  • @69k_gold
    @69k_gold Год назад +2

    Thank you! By learning this I was able to create a toy version of the async coroutines, helped me a lot to grasp the concept of event loops

  • @TylerLarson
    @TylerLarson 2 года назад +8

    Yep, definitely interested in an async video. Especially interested in learning the "python native" async features and components so as to detangle it from all the third-party contributed stuff.

  • @wojasek1223
    @wojasek1223 11 месяцев назад

    Thank you so much for this video, and all of others. I've started reading Fluent Python a couple months ago, but that was quite hard for me to go through it. And you on your channel describe those hard for me things and I finally get them somehow. Thought I was dumb, but all i needed was to find a great lecturer. Thank you so much!

  • @technowey
    @technowey 2 года назад +1

    Thank you for another great video.
    I’ve been using generators for years, and still didn’t know some of this.

  • @DebashishGhoshOfficial
    @DebashishGhoshOfficial 2 года назад

    "Thank you, next" was a nice touch.

  • @pa1nk1ller14
    @pa1nk1ller14 2 года назад +1

    Your videos are going into great depth mate! Im awaiting for that async vid of yours

  • @Cookie-mv2hg
    @Cookie-mv2hg 2 года назад +2

    Every coding courses of yours it like math classes where you start at 1+1 and a simple zone out and suddenly you're on advanced mathematics.

  • @ashishjain518
    @ashishjain518 2 года назад

    I probably only got 20% of this video. But it was enough for me to fiddle around and learn more about generators' daily use cases to improve my performance...
    Great video, Mcoding 😄

  • @trag1czny
    @trag1czny 2 года назад +7

    craving for the async vid 🤤

  • @mistervallus185
    @mistervallus185 2 года назад

    literally just had to learn about generators 2 days ago for a proj. the video timing is immaculate

  • @CrYpt001
    @CrYpt001 2 года назад +1

    Finally something about generators. Never quite got them

  • @yxh
    @yxh Год назад +1

    I would def like a video going deeper into "yield from" generator uses, with examples

  • @blacky7801
    @blacky7801 2 года назад +2

    You can pass things into a generator? Wow, incredible video!

  • @jewpcabra666
    @jewpcabra666 2 года назад +2

    always love the videos - would love an async video! Always learn a little tidbit from these

  • @aditya95sriram
    @aditya95sriram 2 года назад

    That generator pipeline was eye-opening! I've worked with generators plenty, but still this pipeline idea escaped me

  • @murphygreen8484
    @murphygreen8484 2 года назад +1

    Made me realize how much I still need to learn. Great video!

  • @krimsonsun10
    @krimsonsun10 2 года назад

    ALL hail @mcoding High Priest of the Python temple!! Your explanations are succinct, and the usage examples help me so much to grasp the concepts. Thank you.

  • @FlorianLinscheid
    @FlorianLinscheid 2 года назад +1

    Didn't know about generator chaining, that sounded very useful! Thanks

  • @dixonstroi
    @dixonstroi 2 года назад

    I think this will really help me with lazy execution via generators. This would have really helped if . Also, 'yield from' was hard for me to get from just the docs, so thanks for summing that up tidily.

  • @ren200758
    @ren200758 2 года назад

    didn't know about the generator pipeline and was blown away by it. big hype for the async video!

  • @modest_supreme
    @modest_supreme 2 года назад

    Thank you for this! Excellent deep dives. Your videos are a great source for understanding the why/how behind functionality.

  • @vidlb
    @vidlb 2 года назад +2

    Thank you ! And yes for the async video

  • @LastTigerEyes
    @LastTigerEyes 2 года назад +2

    I really appreciate your videos. I always learn something new, even when I don't think I will. TIL parenthesis make generator comprehension. :)

  • @andrewstribling4385
    @andrewstribling4385 Год назад

    Nice work! I cannot wait to start using these generator techniques!

  • @AByteofCode
    @AByteofCode 2 года назад +1

    Very nice CTA at the end, hadn't noticed it before, clever :)
    Otherwise great video and can't wait to know how async uses generators, I've been curious about that ever since you mentioned it a while ago.

  • @redon638
    @redon638 2 года назад

    Thanks! I always learn something new and really impressive watching your videos. Wish you twice as much subs

  • @darske1
    @darske1 2 года назад

    Plot twist: The 1 Gb file you're trying to read, has only 1 line xD
    Awesome video. The send method confuses me a lot every time I see it, I don't know why lol

  • @BR-lx7py
    @BR-lx7py 2 года назад

    This video is definitely eye-opening. I thought that generators were just regular functions that you could re-enter, but I never comprehended how python calls them totally differently. Adding something like "if False: yield" to a regular function totally changes how it is called, despite those 2 lines of code being a noop.

  • @adamstrejcovsky8257
    @adamstrejcovsky8257 2 года назад +1

    when I feel on top of the world with my python knowledge, I go here to restore humility :D

  • @spaghettiking653
    @spaghettiking653 2 года назад +2

    4:44 what is this _make method you call? I wasn't expecting this code to run, but it still did, even though it doesn't appear you defined the method? Is this something generated by dataclass?

    • @NostraDavid2
      @NostraDavid2 2 года назад +2

      Note that MyDataPoint class is the type NamedTuple. I googled for "_make NamedTuple Python" and got some info on the function. Turns out that _make is part of the NamedTuple class.

    • @NostraDavid2
      @NostraDavid2 2 года назад +1

      Also note that's its a NamedTuple and not a data class. This just means that you have different functions that you can use. So no comparison, like you do with data classes. You CAN do it, but you'll have to implement it yourself.

    • @spaghettiking653
      @spaghettiking653 2 года назад +1

      @@NostraDavid2 I see, thanks for pointing it out. So, I'm not sure why I thought it was a dataclass, but I guess I just saw the type annotations and didn't read the top part. That makes a lott more sense, big thanks :)

  • @klaasvaak2575
    @klaasvaak2575 2 года назад

    not just imagination or/and downloadspeed but also your pride deciding what you appropriate from the interwebs or what you painstakingly program yourself in most likely a less efficient methode.

  • @MichalPlichta
    @MichalPlichta 2 года назад

    Wow I thought I know almost everything about generators, but i was wrong! Well done!

    • @mCoding
      @mCoding  2 года назад

      There's always more to learn!

    • @Plann
      @Plann 2 года назад

      Same.

  • @dmdeemer
    @dmdeemer 2 года назад +2

    Watched this video because I'm like, "I know what generators are, but I bet I'll learn something new about them." Found out that yield is an expression. Mind blown. Not disappointed.
    Please make the async video.

  • @PetrSUsername
    @PetrSUsername 2 года назад +1

    I watched quite few videos about async but I would still like your take as well. It is one of the more complicated/complex? parts of the language to grasp.

  • @martinc.7424
    @martinc.7424 2 года назад

    I was just told that list comprehension where faster than for loops... now it makes sense.

  • @PikalaxALT
    @PikalaxALT 2 года назад +3

    4:25 - Pycharm thinks your text file is a requirement.txt.

  • @BRICKSINSILK
    @BRICKSINSILK 4 месяца назад +1

    I have imagination...I just lack drive, passion, purpose, stamina, motivation, IQ, and I essentially am unable understand social ques...

  • @MoritzWallis
    @MoritzWallis 2 года назад +2

    Super informative video, thank you, very interesting

  • @LuckySeer2
    @LuckySeer2 2 года назад +1

    when i started python, i was so proud of my prime number generator function

  • @knut-olaihelgesen3608
    @knut-olaihelgesen3608 2 года назад +1

    Thank you so much. This was a very confusing topic.

  • @endoflevelboss
    @endoflevelboss 2 года назад

    Looking forward to the async video 👍🥳

  • @con-f-use
    @con-f-use 2 года назад

    > "Do you think, they would really introduce a whole new set of keywords just to have a shortened for-loop?"
    Yes. The answer is "Yes, I can see the Python devs do that."

  • @taylorbreutzmann6034
    @taylorbreutzmann6034 2 года назад +2

    It’s crazy, being able to tell how intelligent another human is just behind a screen/video.

  • @macedmondson782
    @macedmondson782 2 года назад

    I'm really liking your videos! I would love to see an async video from you!

  • @anibaldk
    @anibaldk 2 года назад +1

    You cannot see this (hopefully) but I had to give a standing ovation to this one.

    • @mCoding
      @mCoding  2 года назад +2

      I saw it!

    • @anibaldk
      @anibaldk 2 года назад

      @@mCoding 😱😱😱😱😱😱😱

  • @ciCCapROSTi
    @ciCCapROSTi 2 года назад

    Good stuff, I didn't know most of the advanced stuff here.

  • @BR-lx7py
    @BR-lx7py 2 года назад

    @9:08 It's crazy that you can even have the same name for the generator comprehensions, so all of them called "nums".

  • @alexsere3061
    @alexsere3061 Год назад

    "Did you really think they would add a new keyword just to abbreviate a for loop?"
    This is python so yes, yes I did

  • @Blubberland
    @Blubberland 2 года назад

    Thumbs up.
    4:27 This might be a rather be a problem of spell-checking settings than on syntax.

  • @AngryArmadillo
    @AngryArmadillo 2 года назад

    Looking forward to the asyncio video!

  • @Jakub1989YTb
    @Jakub1989YTb Год назад

    9:40 - is there a nicer way to chain the generators like this? To not repeat the "nums" etc?

  • @StephenBuergler
    @StephenBuergler Год назад

    Do you think it would be a good idea for the else clause in the for/in/else loop to be the place where the generator's returned value is made available?

  • @Thr0nSK
    @Thr0nSK 2 года назад +1

    Man you killed it with the Ariana Grande 😂😂

  • @mytalala
    @mytalala 2 года назад

    looking forward for async video, great job

  • @AIRLZ6
    @AIRLZ6 11 месяцев назад +1

    damn i need to watch this video over and over again :D. Love it!

  • @mattlau04
    @mattlau04 2 года назад

    Great video as always! And would love to see a video on async

  • @MaxBloomfield
    @MaxBloomfield 2 года назад +1

    I enjoy your dives under the hood of stuff I routinely use and thought I knew well.
    It might be worth pointing out that generator comprehensions can have closures like functions can:
    def multiples(value):
    return (value * x for x in [1, 2, 3])
    fives = multiples(5)
    for number in fives: # 5 is now embedded in fives
    print(number)
    RUclips comments need code formatting markup. At least on this channel.

  • @yxh
    @yxh Год назад

    So at 9:31, the `nums` on line 15 is really a 5th-level nested generator? And whenever sum() wants the next value in the top-level generator, the inner nested generators wind all the way down to the lowest level to read the file and parse it one row at a time?

    • @mCoding
      @mCoding  Год назад

      Yep, that's right!

  • @tytywuu
    @tytywuu 2 года назад

    I can't wait for the async video!

  • @HonsHon
    @HonsHon Год назад

    Helped me refactor some code and provide some memory savings! Thank you!

  • @morrispearl9981
    @morrispearl9981 2 года назад

    I am a fan of generators. I use "yield from" when the function that generates the next thing happens to be recursive. For example, I have a generator that takes a list of N things, and yields each permutation of those N things, and the underlying algorithm is recursive.

  • @mjdevlog
    @mjdevlog 2 года назад

    So useful, even yhough i don't understand the last half of the video. Maybe one day i will😅

  • @gormster
    @gormster 2 года назад +1

    No, I don’t want a video on asyncio. I want a whole goddamn *series.*

    • @mCoding
      @mCoding  2 года назад +1

      Take note of how I'm methodically making videos on all the prerequisites for a deep async discussion 🙃

    • @khalilhadji6489
      @khalilhadji6489 2 года назад

      @@mCoding can't wait, i am facing some issue in one of my projects and understanding how asyncio works inside out would be very helpfull

  • @vt2788
    @vt2788 2 года назад

    Really advanced high value stuff! Thanks!

  • @bigmacbeta
    @bigmacbeta 6 месяцев назад

    Thank you. Amazing explanation.

  • @StrangeArrow
    @StrangeArrow 2 года назад

    Super Content. Thanks for sharing with us 🥰🥰

  • @zhouyu9971
    @zhouyu9971 2 года назад +2

    I like the Ariana Grande part…..😂

  • @yomajo
    @yomajo 2 года назад +1

    Like 4th year (non-full time) working on Python and this channel consistently keeps me feel stupid. I don't even get how you can call "send" method on a function... I wonder how many years author develops software to know these intricacies of language.
    And 42 reference was observed and appreciated, btw.

  • @thyllmuller4524
    @thyllmuller4524 2 года назад

    9:42 I tried that exact code and I got the "sum is inf" - any idea what might be happening? I triple checked the code, it is identical aside from the function name being different.

  • @mayank8387
    @mayank8387 2 года назад

    Dude you're amazing! Thanks for sharing.

  • @samuelthecamel
    @samuelthecamel 2 года назад

    Start of video: Ah yes, this is a cool useful Python feature that I didn't know about!
    End of video: What is even going on

    • @mCoding
      @mCoding  2 года назад +1

      Haha welcome to my channel! A lot of my videos are guilty of this. I try to make the beginning accessible to everyone but then by the end I'm covering technical details and esoteric use cases that experts get held up on.

    • @samuelthecamel
      @samuelthecamel 2 года назад

      @@mCoding no problem man, it's nice that anyone at any skill level can learn something from these videos

  • @laurentmichel4565
    @laurentmichel4565 2 года назад

    I would enjoy a video about asyncio a lot

  • @stacymaimoon4189
    @stacymaimoon4189 2 года назад

    I was impressed.
    Just one observation: if you try to debug an example (I did it with example_composable()) and you want to see what happens with the data in the generator after each step,
    transforming the generator to a list (I am using PyCharm), you will be surprised to discover that the list (and the generator itself)
    is empty after the very first conversion (and all subsequent generator steps as well).
    The example runs in execution mode, but delivers wrong results if you debug. I have not found a suitable means to overcome this limitation, so far. Do you have any presentable idea?

  • @lawrencedoliveiro9104
    @lawrencedoliveiro9104 2 года назад

    14:44 Yield-from does nothing that cannot be done by the outer generator doing its own send calls on the inner generator.

    • @mCoding
      @mCoding  2 года назад

      True, but take a look at what yield from is defined as in the spec. Due to all the edge cases, it would be an absolute nightmare to implement it yourself every time you wanted to use it. peps.python.org/pep-0380/#formal-semantics

  • @jullien191
    @jullien191 2 года назад

    Muy buen video. Gracias amigo

  • @cloppingemu1471
    @cloppingemu1471 2 года назад

    Look forward to an async video

  • @RoamingAdhocrat
    @RoamingAdhocrat 2 года назад

    What typeface is your editor using? I covet those flat-top 3s

    • @mCoding
      @mCoding  2 года назад

      That's the default font in PyCharm, JetBrains Mono.

  • @greasedweasel8087
    @greasedweasel8087 2 года назад +1

    Can you do a video on making __iter__ a generator vs defining a __next__? I’ve seen both in the wild, you seem preferential to the __iter__ generator, and I’ve googled to no avail. I’m mostly interested in which one is more pythonic, but I’d also like to know what you think the use cases for each are. Great videos!

  • @nassehk
    @nassehk 2 года назад

    Great videos pall. Please make that async video.

  • @efperel
    @efperel 2 года назад

    Yield from is great for trees and other recursive traversals

  • @dmitrylitovchenko2365
    @dmitrylitovchenko2365 2 года назад +1

    In collatz generator checking for n == 1 should be at the top otherwise it behaves funny with input of 1: [4, 2, 1] :)

    • @mCoding
      @mCoding  2 года назад

      Good catch! Yes you are absolutely right.

  • @kylwatson9240
    @kylwatson9240 11 месяцев назад

    Now if only I was doing something complex enough to merit this new found tool in my python bag... One day

  • @arthurfelipe544
    @arthurfelipe544 2 года назад

    what is the use of the line x: float? i tried to search the use of the : in that line but didn't find anything

  • @lohphat
    @lohphat 2 года назад

    What's confusing here is that in the first example you have to use next() to get the next yield value but in the loop the next() is inferred. To me, that just destroys readability as the syntax has changed for no good reason.