[HN Gopher] Show HN: Khan-dl - Khan Academy Course Downloader
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Show HN: Khan-dl - Khan Academy Course Downloader
Author : rand_net
Score : 171 points
Date : 2021-02-14 18:44 UTC (4 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| testfoobar wrote:
| The Covid crisis has exposed a lot of the disaster in public
| education. For many kids, the quality of education they receive
| is a function of the quality of the school and the quality of the
| teacher. This is non-sensical.
|
| Kids can learn from online sources. So why should someone's
| education be tied to their school district or teacher quality?
|
| I would love to have the local school system provide lab space,
| athletics, support services and one-on-one tutoring as necessary.
|
| But the bulk should be delivered online. Sal Khan is
| comprehensive and brilliant, but perhaps someone out there is
| better at chemistry or art history. Regardless, every kid should
| be exposed to the "best" teacher of the subject. Why should a
| child's Algebra education be school or teacher dependent, when
| the best Algebra teacher on the planet is just 256kb/s away.
| throwaway6734 wrote:
| I think you're massively underestimating how difficult it is to
| teach students and how important the bond between student and
| teacher is.
|
| Online resources are incredibly valuable as supplementary
| material but they can't replace the culture and bond of small
| group learning
| testfoobar wrote:
| Even in high performing schools, it is easy to find variance
| in child outcomes dependent on teacher. In nearly all
| schools, the "good" and the "bad" teachers are well known.
| Teachers unions having negotiated tenure after just a few
| years of employment prevent the firing of "bad" teachers.
|
| In poor performing schools, there are multiple reasons for
| poor observed outcomes.
|
| None of these need to happen.
|
| Keep small group learning and have adults support learning.
| But there is no reason for a teacher to explain something
| when Khan academy has already done it and often done it far
| better.
| throwaway6734 wrote:
| Do you have experience teaching a group of 10+ students?
|
| >But there is no reason for a teacher to explain something
| when Khan academy has already done it and often done it far
| better.
|
| You're skipping the often difficult task of getting the
| students to properly engage with khan academy.
| jph00 wrote:
| That's pretty much what https://www.modulo.app/ provides. Small
| groups online (1-5 kids) with each kid doing apps/videos at
| their own pace, and getting help from the tutor as needed.
| Works great for our daughter. She's made a lot of friends thru
| it and accelerated academically a huge amount.
|
| (I have no financial interest - just a customer.)
| dehrmann wrote:
| It's a lot harder to be mentored and inspired by a Youtube
| video than a good teacher who cares, even if you only have one
| of those teachers per year.
| testfoobar wrote:
| The demand for "good" teachers far exceeds the supply.
| ivan_ah wrote:
| Ouff, as someone who has done my fair share of downloading Khan
| Academy content, this will be a lot of work. There are something
| like 20K+ videos, so downloading each of them will take forever
| (think weeks). You might get your IP blocked by youtube in the
| process, and in general, getting the HTML for each page will put
| unnecessary strain on the Khan Academy web servers, especially in
| this moment of hightened need.
|
| Instead of downloading from scratch, I would recommend using one
| of the pre-downloaded and pre-packaged Khan Academy video
| archives: a Kolibri channel or a Kiwix ZIM file. Details provided
| below:
|
| ## Kolibri This is the best open source offline learning app
| (from the same people that made KA-Lite, see
| https://learningequality.org/ka-lite/map/)
|
| 1. Download Kolibri from https://learningequality.org/download/
|
| 2. Browse the list of Khan Academy channels to find the one
| you're interested in (there are 16 diffenret channels, for the
| different languages available from Khan Academy website)
| https://catalog.learningequality.org/#/public?keywords=khan
|
| 3. After installing and starting Kolibri (it's a web app that
| runs on localhost) go to DEVICE > CONTENT > and IMPORT the
| channel you selected in step 2. (Note download will take a while,
| like 8h+ because it will have to download 20k videos, exercises,
| and subtitles).
|
| 4. DONE! You have the entire Khan Academy collection in an easy-
| to-use fully offline learning management system. For bonus points
| you can create separate "coach" accounts as a parent and watch
| your kids progress.
|
| ## Kiwix This is another powerful app developed initially for
| offline browsing of Wikipedia, but now extended to support many
| other sites. Kiwix is based on ZIM files, which are highly
| optimized compressed archives for web content.
|
| 1. Download Kiwix as app or desktop program
| https://www.kiwix.org/en/download/
|
| 2. Find the name of the Khan Academy ZIM file for your language
| and course, search for "khan-academy-" on this page
| https://wiki.kiwix.org/wiki/Content_in_all_languages
|
| 3. After installing Kiwix, import the right ZIM file (again it
| will take a while).
|
| 4. BAM! Now you have all the videos offline (exercises not
| supported in Kixix).
|
| Between the two options, the Kolibri option would be my
| recommendation because you get all the exercises as well, not
| just the videos, but if you're looking just for videos, then
| Kiwix is better.
| Wowfunhappy wrote:
| Is there not a download function built into the website? It's a
| non-profit, they really ought to make those clips available...
| truetraveller wrote:
| Direct downloads would certainly help, but I understand their
| concerns.
| smarx007 wrote:
| I think they don't want to "dilute" their value proposition.
| They are selling to various sponsors the idea is that their
| platform is the key, but if downloaded videos can suffice,
| it's a different story. Every platform these days want to
| control user "journey".
| Wowfunhappy wrote:
| What are their concerns?
| cjsawyer wrote:
| I bet it's to reduce server load. If a user only sticks around
| for one or two sections then if everything was downloaded up
| front the later sections would be wasted bandwidth
| tomc1985 wrote:
| It's to keep control. Plenty of services have offered full
| downloads over the years and bandwidth is cheap. There's no
| reason for them not to offer them unless they're being
| greedy.
| ahepp wrote:
| It seems kinda weird to me to portray them as greedy. Even
| if the root of this decision is because they want money,
| don't they need to fund the content somehow?
|
| Khan Academy seems to have really raised the bar for this
| kind of content. I'm inclined to trust their decision on
| how to maintain quality and balance that with
| accessibility. Maybe I'm just naive?
|
| At the same time, it does seem like having the content
| easily available offline could help people out. I wonder if
| they've ever explained their rationale?
| tomc1985 wrote:
| Because my statement isn't necessarily about Khan
| Academy, but anyone hosting cloud-based video content.
|
| Data wants to be free, as they say, and digital economies
| are a world of abundance where copying is free or nearly
| so. When a provider doesn't align with that they are
| imposing physical-world scarcity economics in a place
| where it doesn't belong.
|
| It feels like people are trying to erase fundamental
| concepts like files or downloading, and instead offering
| a bullshit rental model where anything you can do on the
| net is at the pleasure of the content owner. It is
| disempowering to users as it changes them from masters of
| their domain to digital peons in CC's feudalistic
| kingdoms.
|
| That is what I mean by 'greedy'. If you publish something
| online, it is out there for good. You cannot try to
| delete it and you cannot try to control it. You do not
| have a right to try to profit on the content itself
| because, again, data is free and no matter how much one
| might want to control data, ultimately they can't. DRM,
| ads, subscription gates -- these are all additional
| layers of crap that we have built to cage that data and
| prevent it from being freed.
|
| It is a shame that we as a people cannot handle this
| world of abundance, and that the tools we use to navigate
| it grant us less and less control with every new DRM
| scheme or subscription service.
|
| There are plenty of ways to monetize without locking down
| bits.
| Wowfunhappy wrote:
| > It feels like people are trying to erase fundamental
| concepts like files or downloading, and instead offering
| a bullshit rental model where anything you can do on the
| net is at the pleasure of the content owner. It is
| disempowering to users as it changes them from masters of
| their domain to digital peons in CC's feudalistic
| kingdoms.
|
| This is why I find it so disheartening that Khan Academy
| doesn't allow downloads natively. I understand the
| incentives for a provider like Youtube are overwhelmingly
| in favor of streaming-only, but an educational nonprofit
| like Khan Academy? If even _they_ don 't offer downloads,
| what hope is there?
| [deleted]
| Wowfunhappy wrote:
| Could put up a torrent. I'd certainly seed that.
| thinkingkong wrote:
| Thats not how non profits work. They still have bills and
| alternative methods for viewing may impede their ability to
| earn revenue.
| andai wrote:
| They don't show ads do they? Or is most of their traffic via
| YouTube?
| ben_w wrote:
| If they do so, is there any risk of spiders/obsessive
| collectors downloading _everything_? It's been a while since I
| ran downloads directly off my website, so I'm genuinely not
| sure if there are enough of either to significantly alter
| bandwidth requirements.
| enjoyyourlife wrote:
| The College Board (maker of the SAT) is also a non-profit
| unreal6 wrote:
| Yes, but the College Board is evil in a way I perceive Khan
| Acedemy to not be.
| enjoyyourlife wrote:
| Khan Academy is essentially built around preparing students
| for College Board exams such as the SAT and AP. The College
| Board is even one of Khan Academy's key supporters
| [deleted]
| runawaybottle wrote:
| Is khan academy even worth a shit? The videos seemed kinda
| pedestrian, the narrative seemed to carry it.
|
| Edit:
|
| So, I'll double down on the bitterness. Why Khan? Why not the
| million other people that make instructional videos? Why did this
| guy get funding from Melinda Gates foundation?
|
| If we objectively look at it, I think we'll come to the answer -
| vanity. Indian guy with good cred (well shit, what did you think
| your SAT tutor was supposed to look like?) peddling the shit out
| of the narrative.
|
| Ok, that's fine. Did he do anything more than your standard
| YouTube video? That's all I'm saying, no Popes in this world
| please, no one is above criticism.
|
| Sal khan makes regular ass YouTube instructional videos.
| tchalla wrote:
| What would be more than "worth a shit" in comparison to Khan
| Academy? What process do you use to define the "worth"?
| runawaybottle wrote:
| Platforms that should have integrated with k-12 schools by
| now.
|
| It was a massive failure of the vision more or less.
| [deleted]
| [deleted]
| throwawaysea wrote:
| The vision should be to replace K-12 schools, which have no
| accountability for unionized teachers and poor results
| compared to schools worldwide. We need school choice and
| decentralization, not propping up failing institutions.
| tclancy wrote:
| Not sure your education is finished.
| tchalla wrote:
| Are you telling us that platforms that don't integrate with
| K-12 schools (but are a complement to them) are failures?
| runawaybottle wrote:
| I think at this point, yeah. We have the tech.
| tchalla wrote:
| We also have the tech to have complementary resources.
| You and me don't get to decide success or failure of an
| initiative based on mere existence of technology.
|
| It seems you're quite passionate about labelling
| success/failures from your individual lens.
| vulcan01 wrote:
| Yes, they are "worth a shit" to the millions of students they
| have helped, because videos being "pedestrian" doesn't matter
| when all you need is someone who can explain what your teacher
| tried to cover in class.
|
| They're not meant for people who already have a major in the
| subject -- they're meant for students in the middle/high school
| range.
| runawaybottle wrote:
| I literally only got through calculus in college because of
| this one guy on YouTube:
|
| https://youtube.com/playlist?list=PL58C7BA6C14FD8F48
|
| He doesn't give TED talks, he doesn't have an organization,
| he doesn't have a tech team, and he isn't selling a
| narrative. Probably because he didn't go to MIT, and Harvard,
| and wasn't the _brand_ that could go out and evangelize it.
| But Khan was, so his responsibility is much higher, and he
| mostly failed at it.
|
| I believe in what that guy is doing. What Khan billed himself
| as was unfortunate and we needed to see a lot more from it. A
| glorified YouTube tutor. This thread might as well be a how-
| to on using YouTube-dl to download any number of auxiliary
| help videos on YouTube, not for our pristine Khan, savior of
| education.
| tchalla wrote:
| I understand that Khan Academy isn't a right fit for you.
| But to make personal comments on an individual because they
| aren't a fit for you, is petty. I hope you find more people
| whom you believe in and write about them.
| pwinnski wrote:
| Such an odd criticism, I think. Khan started in 2006 with
| exactly that, online tutoring using YouTube. Is your
| criticism that he ever considered doing more? That he gave
| a TED talk?
|
| Are you asking why Khan is now close to a household name
| while patrickJMT is not? There could be many reasons: Khan
| started 2-3 years earlier, Khan is (now, and for a while) a
| non-profit, arbitrary chance, etc.
|
| Besides, PatrickJMT has 350mm views, has 200 patrons, and
| has published a book, _Calculus for Dummies_. He doesn't
| seem to be doing badly.
| climech wrote:
| Absolutely. Personally, I am forever grateful to Sal for
| helping me overcome my fear of math in my late teens. I
| started from 1+1=2 and eventually got to Calculus and Linear
| Algebra (using KA and other resources). I particularly liked
| the randomized exercises on the site, and how it tracked your
| progress over time. It became kind of an obsession -- I
| thought, if I can learn math, I can do anything. I believe
| Sal's style of teaching had a lot to do with it.
|
| There are tons of other people like me, and it makes me sad
| seeing such bitterness about a person who obviously brought a
| lot of good into the world.
| superbcarrot wrote:
| I found it really useful and anectodally so have many other
| people that I know. From this and your other comments I gather
| that you aren't a fan. That's okay - it's a free resource and
| no one is forced to use it.
| iamcreasy wrote:
| They are incredibly valuable to myself a lots of students I
| know.
|
| He never claimed to be savior of education - he is doing the
| same thing the other youtube guy you linked to - just at a
| bigger scale.
| johtso wrote:
| Is this the kind of thing that can be added to youtube-dl? Are
| they pretty open to adding new sites?
| ehsankia wrote:
| Yeah, despite the outdated name, youtube-dl supports thousands
| of websites, and it seems like it already supports Khan
| Academy:
|
| https://ytdl-org.github.io/youtube-dl/supportedsites.html
| soulofmischief wrote:
| From the description up top:
|
| "A python script to download courses from Khan Academy using
| youtube-dl and beautifulsoup4."
| rahimnathwani wrote:
| khan-dl uses youtubr-dl under the hood
|
| Check the readme or requirements.txt
| itronitron wrote:
| if khan academy sold their courses on DVD I would probably buy
| about 35% of their collection
| HenryKissinger wrote:
| Or the whole collection at a 65% discount?
| unixhero wrote:
| Paging /r/datahoarder
| gnicholas wrote:
| Good timing considering that Khan Academy will be taking their
| MCAT prep offline later this year. [1]
|
| Apparently another org will be hosting them through the end of
| 2021.
|
| 1: https://www.khanacademy.org/test-prep/mcat
| Aliabid94 wrote:
| What was their justification for this? Even if they want to
| focus on high / middle school level content, I assume MCAT
| content doesn't go stale quickly so they wouldn't have to spend
| resources keeping it up to date.
| virtue3 wrote:
| It's also you need a team (or a PM or two w/ the ability to
| pull tech resources) of people that are focused on MCAT.
| Anytime you just leave something static as an org it will rot
| away in usefulness very quickly.
| Wowfunhappy wrote:
| So just hide it, and put up a warning message at the top
| that the course is no longer updated. Why do they need to
| take it down? It won't consume bandwidth unless people
| actually use it (in which case, they must find it useful),
| and I can't imagine raw disk space is a concern. Or, if it
| is, throw up a torrent so at least people can grab the
| data.
| kkaranth wrote:
| Nice! These sort of tools are immensely useful for learners with
| a spotty internet connection.
| smarx007 wrote:
| Almost everything worthwhile I stumble upon gets archived to my
| private ArchiveBox instance these days. Sadly, there are a few
| Coursera/EdX courses that have been taken down (eg
| https://www.edx.org/course/engineering-the-space-shuttle) and
| coursera-dl/edx-dl seems to be broken OOB these days...
| zakki wrote:
| Mind to share how do you build your Archivebox?
| jbc1 wrote:
| There's software called ArchiveBox, it's not a thing they
| made up. Or are you aware and you were asking how to use it?
| galkk wrote:
| I will comment about larger scale. Recently I realized that if I
| find something interesting, it's worth downloading and saving it
| immediately.
|
| I may never use it again, so simple garbage collection script
| does it for me, but it's much better than going to
| youtube/another source and find something "author made video
| private", "channel was removed".
| bhargav wrote:
| How often does that happen to you? I basically just watch
| Youtube videos all day, and often dig up old playlists and
| lectures. This hasn't ever been a problem for me. In my case,
| if I were to do it, this would basically be me being a hoarder
| :)
| imglorp wrote:
| Berkeley posted a bunch of free course content. They got sued
| under ADA because they hadn't captioned the material. Rather
| than go back and caption everything they removed the
| material.
|
| Another example was Walter Lewin's physics videos all got
| pulled by MIT from Open Courseware (but are available on YT
| at least).
|
| Not a comment about the parties involved, just saying there's
| external factors sometimes that will vanish a video.
|
| https://www.insidehighered.com/news/2017/03/06/u-california-.
| ..
|
| https://www.insidehighered.com/news/2015/03/10/despite-
| mits-...
| japanuspus wrote:
| Also https://news.ycombinator.com/item?id=13768856
| cush wrote:
| Wait, Walter Lewin's videos are gone...?
| rel wrote:
| MIT policy on sexual harassment was found to be violated.
|
| https://news.mit.edu/2014/lewin-courses-removed-1208
| ajsnigrutin wrote:
| So what? Report him to the police, do an investigation,
| fire him if he really did what he's accused of, let the
| court deal with the rest... I don't know why removing him
| from the internet helps.
| rvp-x wrote:
| My initial gut feeling was your response, but changed my
| mind quickly when reading the article. His videos being
| online resulted in interaction with the students, and
| that's where he harassed them.
|
| It's a shame, but any other solution feels like it's a
| broken stair just waiting for someone to trip over it.
| Jiocus wrote:
| Removing a persona non-grata and their related authored
| material may serves multiple purposes:
|
| - The organization signaling to stakeholders that they
| condemn and take appropriate action against behaviour.
|
| - The organzation engaging in damage control, minimizing
| future exposure of events linking back to the
| organization.
|
| - Penalizing transgressive behaviour in a professional
| setting, through sanctions and revocations of merit,
| reputation, licensing or employment etc.
|
| Actually, breach of contract could lead to lecture
| material not being legally available, if a lecturer has
| sole ownership of such. It could also be that future use
| of say, recorded lectures, involves compensation to the
| author. If an organization want to cut ties to the
| author, or just withhold compensation for a time, they
| might refrain from using the authors material.
| trianglem wrote:
| Depends on what you're looking for. I'd say anecdotally it is
| between 5-15% missing for me.
| enriquto wrote:
| > How often does that happen to you?
|
| Even if it happens only once, it may be a really sad event. I
| had a "go-to" youtube video (nothing relevant in the grand
| scheme of things, just a beautiful rendition of a famous
| neapolitan song in the original language, not in italian). I
| listened very often because it cheered me up. Now it's gone
| for good and I'm sure I won't ever be able to listen to it.
| It was not a record, just a lady singing in a public place,
| obviously recorded with a phone.
| DanBC wrote:
| It happens a lot for music.
| tomc1985 wrote:
| Quite common, depending on what you're after.
|
| Pornhub and its sisters recently dumped pretty much
| everything by unverified users thanks to an NYT hit-piece.
| Depending on your interests a lot of content went goodbye.
|
| Youtube frequently delists music videos.
|
| Creators sometimes remove old videos for various reasons.
|
| Shit like this is why the cloud is not to be trusted.
| kleer001 wrote:
| > Shit like this is why the cloud is not to be trusted.
|
| Exactly.
|
| No such thing as "the cloud" it's just other people's
| computers.
| [deleted]
| judge2020 wrote:
| > Youtube frequently delists music videos.
|
| I think you mean companies/YouTubers themselves - YT
| doesn't remove regular videos on their own very often. The
| content being deleted is still a problem and reason to save
| it though - many externalities might be reason for the
| uploader to remove videos (legal, purging a Google account,
| etc).
| tomc1985 wrote:
| They do, through DMCA enforcement. But you are right that
| it is a combination of YouTube, publishers, and creators
| delisting things
| qwertay wrote:
| Don't even trust "private" cloud storage. I used google
| docs in school and randomly they locked one of my documents
| that I needed to work on citing "tos violation". Week later
| the document was unlocked but I will never trust them
| again.
| Rebelgecko wrote:
| When I look at my favorite'd videos on Youtube, a huge
| fraction of the ones from before 2010 are gone (example:
| https://i.ibb.co/31vb8nd/Screen-
| Shot-2021-02-14-at-2-31-56-P...). OTOH a lot of the things
| that I found funny in 2009 now seem cringy to me, so the gaps
| in the playlist save me from uncomfortable introspection.
| ajsnigrutin wrote:
| I find a bunch of things on youtube, videos longer than 1
| minute, that i add to "watch later" list, to well... watch
| later. Some things i watch the same day, some are there to
| stay.
|
| Around 10-20% of the older videos are gone... from copyright
| infringements (music in video), to deleted channels, to "not
| available in your country). What I hate the most is, that
| even the video titles are removed, so i have no idea what's
| gone, just the "[Private video]" or "[Delted video]" in the
| list.
| sneak wrote:
| My old youtube favorites are full of [deleted video]. It
| doesn't even tell me what the title was, so I can't even
| begin to reconstruct the playlist from other sources.
|
| Right down the memory hole. Your "favorites" aren't even
| yours.
| TeeMassive wrote:
| Not OP, but I had a YouTube playlist that really was a
| collection of memories since I began university 10 years ago.
| Lots of things that are related to precious memories I had
| there: memes, inside jokes (so many Skyrim references), etc.
|
| It had over a thousand videos from what I remember in 2015.
| Now there's barely ~600 left. Lots of them got deleted due to
| copyright, the Vox Adpocallispe (thx Carlos Maza) and cancel
| culture.
|
| I just downloaded all the remaining video using youtube-dl
| but I should have done that before, now it feels I lost
| something important in those memories that I will never get
| back.
|
| Here's the command I used, took me a while and might save
| other people a few hours:
|
| pip install --upgrade pip
|
| pip install youtube-dl
|
| youtube-dl.exe -i -f bestvideo+bestaudio --merge-output-
| format mp4 "https://www.youtube.com/playlist?list=XXXXXXXXXXX
| XXXXXXXXXXX..."
|
| Obviously if you're not on Windows remove the .exe
|
| This will download an entire playlist at the highest video
| and audio quality and will not crash if a video has an error.
| userbinator wrote:
| Note: even on Windows you don't need to specify .exe,
| unless there also happens to be a .com or .bat with the
| same name in the PATH.
| waynesonfire wrote:
| Ofteb enough that it's worth addressung
| austhrow743 wrote:
| Replace YouTube with porn and it happens all the time.
| mushishi wrote:
| It's common. It's easy to notice if you save interesting
| videos to a playlist and go through them, say, a year or two
| later to find what to watch. And you don't even know what was
| deleted.
| galkk wrote:
| Anecdotal, but in all my "watch later" playlists about 5%-10%
| videos now are "Deleted video".
| TeeMassive wrote:
| Youtube-dl can be used for other sites too. Personally I use the
| extensions: Snap-Links for opening multiple links at once and
| then Export Tabs URLs to copy them all and then pipe this to a
| script.
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(page generated 2021-02-14 23:00 UTC)