Live coding 5

00:00:00.960 | All right, I will start recording.

00:00:02.640 | I wanted to start with an issue which I can't remember. Mark or Matt, somebody pointed out that

00:00:19.200 | their paper spaces were broken. Yeah, so anybody else who's been following along probably found

00:00:29.200 | the same thing that they couldn't see their notebooks anymore, which is a bit of an issue.

00:00:38.000 | So let me start an instance and we can see it create.

00:00:49.440 | Oh, and I should share my screen, I suppose. Share screen, advanced, portion of screen.

00:01:02.080 | Okay. Let's go there. And.

00:01:29.120 | Right, you guys can see my paper space window now. Cool.

00:01:35.600 | All right, so I'll delete the workspace URL as we do.

00:01:55.040 | Start. Okay, while that's starting up, I'll show you the other thing, which is

00:02:06.080 | I mentioned the other day when we were talking about how do we create bash scripts.

00:02:16.320 | For example, we created that bash script run. And I said, oh, you know, you can

00:02:22.160 | use the Jupyter text editor if you want. But that's not how I would do it myself.

00:02:28.320 | And I said, I would show you how I would do it myself.

00:02:31.040 | And the way I would do it myself would be using a program called Vim. And Vim's a text editor,

00:02:42.960 | which has a somewhat deserved reputation for being a bit obscure and challenging,

00:02:54.320 | but also for being powerful. And all of those things are true. And it's kind of something I

00:02:59.760 | wouldn't normally cover in a beginner's guide, but in a guide of the things that are going to

00:03:06.480 | make your life better, I would certainly say, yeah, we do need to include it because it's actually

00:03:12.160 | really quite terrific. But I don't want you to take my word for it. I wanted to

00:03:18.400 | give you an example of how it works and why it's terrific. And so I thought a good example

00:03:28.400 | was one of the folks who's been following along on these. Let me just try to make this bigger.

00:03:39.840 | So I can see more faces. There we go. One of the folks who's been watching these courses,

00:03:44.880 | Daniel has been kind enough to create these timelines, which I think are actually really

00:03:53.360 | useful to remind yourself of what we covered. And they're useful for me because I can

00:04:06.560 | use them to create timestamps in YouTube. So timestamps in YouTube, if I'll just show you an

00:04:14.240 | example. You see how at the bottom here, those little chapter markers appear?

00:04:25.280 | And to make them appear, you basically have to have times in a particular

00:04:35.520 | format in the description. So I actually used Vim to turn Daniel's

00:04:41.360 | thing into those timestamps. And I thought that might be just a good example

00:04:49.040 | of how Vim's a bit different to your average editor. By the way, you might have noticed when

00:04:56.320 | I selected this, I actually selected it quite quickly. And the reason I did that was with

00:05:01.520 | the keyboard. Most things I use have good keyboard bindings and

00:05:06.640 | the forums have good keyboard bindings. If you just hit question mark, you'll see them.

00:05:13.840 | But they tend to be pretty consistent across programs. And you'll see that

00:05:20.080 | J and K move the selection up and down. So if I press K, it moves the selection up.

00:05:30.720 | And if I press J, it moves it down. And it kind of selects it. And then if I hit A, it edits it.

00:05:38.800 | So now I can hit Apple A to select all, Apple C to copy. And you'll see that these keyboard

00:05:49.280 | shortcuts have a lot of overlap with Vim. And so it's kind of nice that as you do more stuff with

00:05:55.280 | the keyboard, you start to realize you don't have to relearn everything from scratch.

00:05:58.560 | So I only just set up this Mac. And so I just installed Vim literally before

00:06:09.760 | we started this session by typing "brew install vim." Because I'm trying to use a Mac a little bit.

00:06:18.080 | And you need to set up Homebrew, which you can do from their website. And so when Vim opens,

00:06:27.840 | this is what it looks like. It's going to be pre-installed. I assume this is now running.

00:06:34.640 | It should be pre-installed on PaperSpace. So we should be able to use it straight away there as well.

00:06:45.920 | It's taking a while to start for some reason.

00:06:56.400 | >> Hello, I suppose it's sitting at the end of this session.

00:07:15.840 | >> It's taking a while for me to...

00:07:19.760 | >> Yeah. That's okay. I don't have to watch it doing that. So while we're waiting,

00:07:31.280 | I'm just going to go back to this one on my Mac. Okay. So here's Vim. So the first thing you'll

00:07:35.360 | notice if you start Vim... So if you're on... Actually, let's talk about different options.

00:07:42.720 | So on Linux, to run Vim, you would type "sudo apt..." Actually, let me do it in the Vim window

00:07:55.920 | because otherwise it's going to autocomplete things in annoying ways. So in Linux to install Vim,

00:08:00.640 | if you don't have it already, you would type "sudo apt install vim." On Mac, you would type

00:08:07.440 | "brew install vim" after you've Googled for Mac, Brew, and installed Homebrew. Windows is going to

00:08:15.760 | be the same as Linux, of course, because it is Linux and WSL. And so once it's installed,

00:08:25.120 | you can just type Vim at the command line. And yeah, the window appears. And one thing you'll

00:08:33.520 | notice is if you start typing, nothing happens. Text doesn't appear. So that seems like a problem,

00:08:38.960 | a text editor where when you type, it doesn't put text on the screen. What on earth is going on?

00:08:43.600 | Well, it's exactly actually the same as Jupyter Notebook, which is in Jupyter Notebook

00:08:48.960 | when it appears. So if I create a notebook...

00:08:55.440 | If I start typing, nothing happens either, right? And that's because in a notebook, you know,

00:09:03.120 | you have to click inside a cell or press enter to go into edit mode. And then if I press escape,

00:09:09.360 | I'm now in command mode and buttons do things rather than type. So for example, x cuts.

00:09:14.800 | Vim is the same. It's modal. You're either in a mode where you're entering and editing text,

00:09:21.200 | or you're in a command mode. So by default, just like in Jupyter, you're in a command mode.

00:09:26.320 | So to go into edit mode, you press I. I stands for insert. So I can start if I press I, and it says

00:09:33.360 | down at the bottom here, insert. So now in insert mode, now if I type, it types. And then if I want

00:09:40.080 | to go back into command mode, I press escape. And if you don't see a mode, that means you're in

00:09:46.160 | command mode. My arrows keys work as usual. And up and down work as usual. But one thing you might

00:09:56.560 | notice is in command mode, the same buttons that we use in discord for up and down J and K also

00:10:02.080 | work for going up and down. And it's not just J and K, it's actually all the letters in a row

00:10:07.680 | there are all movement. So J and K go up and down, and L and H go left and right. It's totally fine

00:10:15.200 | to use the arrow keys in your keyboard as well. And I would say honestly, probably for the first

00:10:20.480 | couple of years of using VM, I always use the arrow keys. At some point, I started using

00:10:26.480 | HJKL all the time instead. I guess my fingers noticed they were a bit closer and I didn't have

00:10:32.800 | to move. And they decided that they liked doing that better. That's fine. So yeah, so you can move

00:10:40.960 | around. And so at this point, we can run VIM, we can enter text. And then the one thing we don't

00:10:49.120 | yet know how to do is to exit and save. So I almost never just type VIM. I almost always VIM

00:10:57.680 | something. I want to VIM a file. So for example, let's say I wanted to VIM my .Z profile file,

00:11:07.440 | which is one of the startup scripts that's run automatically when you start the terminal,

00:11:11.840 | I would type VIM space .ZP tab. And there it is. Okay. And so this is something that

00:11:19.680 | Bruce installed for me. So if I wanted to now edit this, maybe I wanted to put a comment above here,

00:11:24.960 | I want to go into edit mode. And I'll show you like the slow way to do this. I could press

00:11:30.000 | I for insert, I could press enter, I could press up, and I could start typing. So that'd be one way

00:11:37.360 | so I could type my comment. Okay. And then press escape. Now, I want to show you a different way.

00:11:45.680 | So I want to undo all that. So to undo the last thing you did, it's press U for undo, and U again.

00:11:52.160 | I is not the only way to go into edit mode. There's lots of ways to go into edit mode,

00:11:57.840 | to go into edit mode in different places. And one of them is to press O, which opens a new

00:12:04.960 | line underneath. So that puts a new line underneath edit mode. And I want a new line above,

00:12:10.560 | which is shift O. Shift O is a new line above. So it's pretty common that like a letter and

00:12:15.680 | the capitalized version of the letter in VIM are kind of related versions of similar things.

00:12:25.280 | So if I could put a comma here, shift O, auto added by homebrew installer, for example. Okay,

00:12:34.640 | that's good. So now I want to save and close. So there's actually a third mode. There's not just

00:12:41.680 | command mode and edit mode. There's also a mode they call EX mode, which is where you hit colon.

00:12:48.160 | Now, when you hit colon, our cursor moves to the bottom, and you can enter various different

00:12:53.520 | commands here. So one of the commands you can enter is W for right. And so that will save.

00:12:59.440 | So by default, it saves it to whatever I loaded it as. So it saved it back to .Z profile. I could

00:13:06.640 | save it to something else by going W, you know, backup profile or something. And that would save

00:13:13.360 | it to that file name. Another useful EX command is Q, which quits. So colon Q quits. So if I now

00:13:26.400 | decide I don't want to capitalize that, so I'll change that to a small a,

00:13:31.520 | you can combine EX commands together. So to save and quit, you would type colon WQ right and quit.

00:13:42.560 | And so when people say how do I exit VIM, you'll normally hear people say colon WQ.

00:13:49.040 | That's why. And so by the way, what I just did there when I changed the big A to a small a,

00:13:55.520 | I did that in a single button press. And that's because the tilde command changes case

00:14:04.080 | and moves one to the right. Okay. So this is an example of, you know, when you've got the whole

00:14:10.240 | keyboard available and shifted versions available, like there's a lot of things you can add, right?

00:14:16.560 | And then hit you a few times. So if I wanted to change the case of the next 10 letters,

00:14:25.440 | I could hit tilde 10 times. One, two, three, four, five, six, seven, eight, nine, ten. Okay.

00:14:32.480 | But I wouldn't do that because in VIM, you can always say before you do a, call it a verb,

00:14:45.040 | before you do like one of these, you know, letter command, single letter commands, you can type a

00:14:50.080 | number, which is how many times do you want to do it? So if I type 10, so if I type 10 tilde,

00:14:56.800 | it runs at 10 times. And so this is where things start getting interesting, right? Because every

00:15:06.720 | single, you know, verb you can run in VIM, you can also say how many times to do it.

00:15:20.960 | So for example, to delete a line, let me just create, oops, I've accidentally created far

00:15:28.320 | too many lines. So to delete a line, you press DD. To delete five lines, you just press 5DD.

00:15:34.800 | Okay. So it's important to remember like everything you can do. You can put a number after it.

00:15:44.640 | But actually, it's even more powerful. Because after most commands, you can also say, you can

00:15:53.840 | add something called a motion. A motion, for example, is right arrow moves right one, left arrow moves

00:16:00.320 | down one. Shift G goes to the bottom of a file. Motions are things that move your cursor around.

00:16:06.560 | Now, that doesn't sound very exciting. Unless I tell you after a command, you can type a motion

00:16:13.920 | and the command will apply to the region that that motion covers. So for example,

00:16:18.960 | I'm currently on line three. And if I press shift G, shift G is the motion to go to the end of the

00:16:24.160 | file. D is the command to delete. So I can combine these together. D, shift G will delete to the end

00:16:32.080 | of a file. D, shift G. Right? So that's pretty interesting. So GG takes you to the start of a

00:16:43.200 | file. So to delete from here to the start of a file, D, G, G. Right? Or, you know, there's some

00:16:49.760 | really interesting motions. For example, let's create two bits. Right? There's a concept of a

00:16:59.520 | paragraph. So right curly bracket takes you to the end of a paragraph. It takes you to the end to the

00:17:05.120 | next empty line. Right? Press it again. So that means if I want to delete everything from here

00:17:12.800 | to the end of the paragraph, I would kiss D, right curly bracket. Okay? Or if I want to do that twice,

00:17:21.280 | so delete from here to the end of the paragraph and also delete the next paragraph. Actually,

00:17:27.600 | so let me show you. I want to copy this whole second bit and make a copy of it. So in VIM,

00:17:35.280 | copying something, it's not control or command C, it's called yanking. So you press Y. So I want to

00:17:41.760 | copy the next paragraph. So to copy this paragraph, I would press Y, right curly bracket. Okay? And

00:17:48.080 | then to paste its P, and by default, it pastes it to the line underneath. To paste it to the line

00:17:54.080 | above, you won't be surprised to hear it's shift P. So there's a copy. Now I want to go down to the

00:18:00.000 | next paragraph and change that to third bit. So I'll press right curly bracket. And I now want to

00:18:07.840 | delete this word and replace it with a different one. Deleting and replacing in VIM is called

00:18:13.360 | changing. And that's C. And so like everything else, that can be combined with a motion.

00:18:18.960 | So the motion to move to the next word is W. W goes to the next word, right? B goes back a word.

00:18:27.040 | So to delete this word and let me start typing in a new one, it would be change word, C, W, third bit.

00:18:36.880 | Okay? So if I want to delete from here to the end of the paragraph and the paragraph underneath,

00:18:44.240 | I can just delete two paragraphs. So that would be 2D, right curly bracket.

00:18:50.000 | Okay? So I would describe this as being highly compositional, right? You can kind of combine

00:18:59.680 | numbers, motions, and commands together. And then we haven't even touched on

00:19:10.000 | EX, right? So let's talk about EX. So I'm going to delete to the end of the file,

00:19:16.320 | D, shift G, and delete this line, DD, and colon WQ to exit. So I mentioned that we wanted to

00:19:30.720 | change this into something suitable to put in a YouTube video. So I press E, Apple A, Apple C,

00:19:40.480 | cancel, and then I'll go VIM, I don't know, temporary, insert, Apple V,

00:19:51.040 | GG. Okay. So here I've just pasted in this text, right? And I want to clean this up. So

00:20:01.360 | I want to clean up the title. So I'll just press DD. And I want to do the same thing to the next

00:20:08.640 | line. So to do the same thing you just did again, press dot. So that's going to delete the line

00:20:15.680 | again. Now, where this gets interesting is that will redo the entire, like, number, command,

00:20:26.000 | motion that you just did. So for example, if I press 4DW to delete four words, 4DW to delete

00:20:32.240 | four words, and then press dot, that deletes another four words. And so that can get

00:20:38.560 | pretty interesting. So for example, oh, okay, I'll show you a really cool example.

00:20:44.640 | To search in VIM, you use slash, which is pretty common in a lot of different tools. And so if I

00:20:57.680 | want to search, I don't know how many of you are familiar with regular expressions,

00:21:01.280 | but you can put any regular expression here. If I wanted to search for the next timestamp that

00:21:06.080 | Daniel created, I'd want to find a digit at the start of the line, right? So to go to the next

00:21:12.160 | place where there's a digit at the start of the line, regular expressions use caret for start of

00:21:16.480 | line and backslash D for digit. So this is going to search, there you go, and selects the next

00:21:22.400 | digit at the start of the line. To search again, press N, N, right? So this is kind of cool, right?

00:21:31.040 | Because what we could do now is if I want to delete everything up to the next digit at the

00:21:37.280 | start of the line, well, slash is a motion. So I could type D slash caret backslash D,

00:21:45.520 | and that searches for the next digit at the start of the line and deletes to it.

00:21:50.320 | And so now I want to do it again, I press down, I'll just press dot.

00:21:56.880 | So now I'm removing everything that's not a chapter header. So that's pretty interesting.

00:22:06.640 | And then I could just delete to the end of the line with D shift G and delete the first line,

00:22:12.400 | and I'm just about done, right? Of course, there's more than one way to do it. So let's

00:22:17.520 | look at a few different ways. Another way we could do it is we could delete all the lines

00:22:25.680 | that start with a hyphen. So there's a really useful EX command, which is the command

00:22:31.680 | G. G is, I think it stands for grep, it searches for things, and it does an action

00:22:41.280 | to anything, any line that it finds. So with any EX command, you first of all have to say,

00:22:48.640 | what lines do you want to apply it to? And nearly always, you want to apply it to all lines,

00:22:54.000 | which is percent. So generally speaking, for most EX commands, you'll start with percent.

00:22:59.760 | And then you say, what command do you want to run? So I want to run G, which is I'm searching for

00:23:04.720 | something. And then in EX, the different parts, the kind of the different parameters are generally

00:23:10.000 | separated by slash. So the next thing is, what do you want to search for? I want to search for,

00:23:17.360 | at the start of a line, a hyphen. Okay, and then another slash. Okay, what do you want to do?

00:23:22.880 | And now I can put in any vim command. And so remember the command to delete in vim is D.

00:23:27.920 | So this is going to search for anything with a hyphen at the start of the line and delete it.

00:23:33.840 | There we go. Okay, so we could now do a similar thing to delete all the empty lines.

00:23:40.800 | So to delete all the empty lines, I would do percent G slash. Okay, I want to do any time

00:23:46.160 | you've got the start of a line, followed by zero or more spaces, followed by the end of a line.

00:23:53.120 | That's an empty line. What do I want to do? Delete it. Okay, so. And then finally, I want to put a dash

00:24:03.200 | between that first space and the thing after it. So that's a search and replace. So again,

00:24:09.920 | we do colon percent to apply some ex command to the whole file. S for search and replace.

00:24:15.760 | Then the slash to put in our different parameters. So first, what are we searching for? A space.

00:24:21.520 | And then what are we replacing it with? Space hyphen space.

00:24:25.120 | And then enter. And so this will just apply it by default to the first time it finds it.

00:24:31.680 | Okay, so that's like an overview of like why VIM is cool. Like when people say VIM is cool,

00:24:40.880 | they're not saying like, oh, you should use it because it's retro and interesting.

00:24:44.160 | They're saying you should use it because it's powerful. And specifically, data scientists

00:24:48.720 | should learn VIM because this interactive text munging is what we do with input data files and

00:24:56.800 | output data files all the time. And something we can look at later if we want to is it's

00:25:03.120 | super easy to create macros in VIM, which is where like literally it will just record

00:25:08.320 | each button you press. And then you can just rerun that macro. So if you want to rerun the

00:25:13.520 | same process on six different files, you just run the macro six times. Now, in this case,

00:25:22.800 | I want to close without saving. So normally if I go colon Q and it says, no, you haven't

00:25:27.680 | saved. So it's kind of careful to help you there. It says add exclamation mark to override. So I'll

00:25:32.560 | do that Q exclamation mark. Okay. So we can use that in

00:25:49.280 | in Jupyter. And so now we're going to fix the problem, which we talked about earlier,

00:26:01.280 | which is how come our files disappeared? And to fix it, we need to edit prerun.sh. So if I type

00:26:12.880 | vim prerun.sh. So here we've got this. And the reason that the files disappeared

00:26:19.920 | is that at the start of our script, we typed CD, and that changed to our home directory. And we

00:26:27.600 | never went back to where we were. And so that meant when it ran Jupyter, it ran it from our

00:26:31.680 | home directory. This is actually currently showing the contents of our home directory.

00:26:35.680 | Now, okay. I want to show you now how we know this by looking at run.sh. I want to switch to editing

00:26:43.760 | run.sh without saving where I'm up to. And I want to show you a really neat thing in Linux that

00:26:51.600 | lets you do this, which is control Z. Control Z does something really interesting. It stops the

00:27:00.000 | process I was running, and it puts it in the background. So if I type jobs, I can see what's

00:27:04.640 | running in the background. Vim is running in the background. I can do anything I like. And then

00:27:09.600 | any time I want, I can type fg for foreground, and it comes back to where I was. So I can hit

00:27:17.600 | control Z, and then I can type vim slash run.sh, which is actually what I was going to show you.

00:27:25.440 | This is the thing that they run for us when we start an instance. And you can see here it runs

00:27:31.680 | our script, and then it runs Jupyter. So our script was CDing to our home directory, and then

00:27:37.680 | running Jupyter. And so Jupyter was in our home directory when it ran. So I go to colon queue to

00:27:44.080 | exit that, and I'll go fg. There we go. Now, optional power user thing, which I use a lot,

00:27:54.000 | is I would not -- that's not how personally I would have looked at the run.sh file. To look at the run.sh

00:28:01.600 | file, what I would do in Vim was I would type colon sp, which stands for split, slash run.sh.

00:28:07.680 | And as you can see, vim actually allows me to have multiple windows open at once. Okay. Kind of like

00:28:16.640 | tmux, actually. tmux and vim has very similar functionality. And so then I can, you know,

00:28:22.240 | scroll around here. And then in vim, instead of pressing control B and an arrow to go to a different

00:28:29.520 | window, which is tmux, in vim it's control W. So except that control W closes a tab in Chrome,

00:28:38.320 | so that's possibly not going to work. Okay. So there's a couple of ways we could solve this.

00:28:51.200 | The probably the best way in a script is to use that trick I showed you last time, push D.

00:28:57.520 | Tilde is our home directory. So that's the same as CD, changes to our home directory,

00:29:03.040 | but it remembers where we were. And then pop D puts us back to where we were before.

00:29:08.480 | So that should fix our problem. Okay. So this untitled.ipynb, we'll probably find that -- yeah,

00:29:21.520 | see here it's in our -- here it is in our home directory, which was not what we intended.

00:29:26.400 | So let's delete it.

00:29:27.920 | And we'll shut this down.

00:29:34.320 | And then we'll create another instance just to check that worked.

00:29:49.760 | Okay. So while we're waiting for that to get started, does anybody have any

00:29:54.160 | questions or comments about vim?

00:29:56.960 | Hi, Jeremy. That is very good. That took me back to a previous life where I used to install

00:30:05.440 | WordPerfect on Unix boxes and is working in a legal firm and said, what do you use for a

00:30:10.960 | word processor today before I put on WordPerfect? And this person, you know, legal secretary said,

00:30:18.480 | I use VI, which is like, vim is VI improved or VI improved. But it's just amazing, the power of it,

00:30:27.200 | if you know everything it can do, it's a perfect word processor.

00:30:33.360 | Yeah, it's great. I mean, I don't use it as a word processor, to be clear. I use, you know,

00:30:40.240 | Microsoft Word or Google Docs as a word processor, because I think they're very good word processes.

00:30:45.200 | But for a text editor, I use it a lot. If I've got, you know, a CSV file, I, you know,

00:30:51.520 | want to do some quick cleanup to or something like that. Or a log file. I'll use it. Yeah,

00:31:01.280 | pretty much any time I'm editing a quick script or something on a terminal. It's that's great.

00:31:10.400 | You know, I will say Visual Studio Code is also excellent. And I wouldn't say like vim is

00:31:19.280 | better or worse than Visual Studio Code. I use both of them. I use vim more often

00:31:24.720 | than Visual Studio Code, but I do use both of them. And in fact, there is a button here,

00:31:28.800 | I thought somewhere. I thought there was like an open Visual Studio Code button,

00:31:39.200 | but maybe I'm imagining things. Or maybe it has to wait until it's finished opening the server.

00:31:50.240 | Oh, here it is. Yeah. So there's an access remote kernel actually lets you connect Visual Studio

00:31:58.320 | on your machine to the remote machine. So you can even use Visual Studio remotely. You can also

00:32:06.000 | use it in WSL on Windows. Don't install Visual Studio Code into the Linux box, install it into

00:32:13.280 | the Windows box, because it's got a WSL connector built in. So it uses it treats WSL, you know,

00:32:21.040 | just as if it's a local Windows directory. You can also connect to any SSH instance using the

00:32:27.200 | VS Code remote connector or yeah, this remote kernel thing. So, you know, you showed a lot

00:32:38.240 | of keyboard shortcuts for them, right? So how can someone approach learning it? Because it feels a

00:32:44.320 | bit intimidating when you're a beginner. Yeah. Yeah. So I mean, the trick with

00:32:51.520 | learning something new is to try and like do it in small chunks, right? So don't expect to learn

00:32:59.440 | all of them. Like, so at this point, I would say learn I just start inserting things, arrow keys

00:33:07.200 | to move around, escape to go back to command mode, colon WQ to close and save. And at that point,

00:33:14.160 | you can now use Vim to edit your shell scripts and stuff. And then like try and learn maybe one

00:33:22.880 | or two new commands each day. So, you know, one useful one, you know, or emotion each day. So,

00:33:30.160 | you know, W and B are useful to know to move forward and backward a word.

00:33:35.040 | And yeah, there's a lot of Vim tutorials and things out there. So, for example, here's

00:33:42.800 | OpenVim.com, which is going to introduce you by saying, oh, hit the enter key. Like, okay,

00:33:50.080 | I'll hit the enter key. And so you could work through a tutorial like this. Yeah, it's

00:33:55.360 | we all get intimidated, honestly, Kurian, when we see an expert working with something that we

00:34:04.880 | don't know yet. And at first, it's like, wow, that's powerful. I wish I could do that. But my god,

00:34:10.240 | you know, how would I ever get to that point? And the goal is not to be an expert at Vim. The goal

00:34:16.080 | is to like be able to do Vim to like slowly do something that you want to be able to do.

00:34:21.040 | And this is one of the things I, you know, really had to practice to myself in my late teens and

00:34:26.240 | early 20s was to repeatedly put myself in a position where I was intentionally doing things

00:34:34.400 | slowly by using a tool that I wanted to know. And I was pretty sure at some point would be useful,

00:34:40.000 | but I didn't know well enough to do it faster than with other than some other tool. So I've always,

00:34:45.360 | you know, since since like 16 been pretty good at using Lotus one, two, three and Excel spreadsheets.

00:34:51.760 | And I tended to turn to them for everything. And then I wanted to learn SQL databases. So I kind

00:34:59.040 | of forced myself to do things involving lists with databases for a while, even though I got

00:35:03.440 | slower. And then I was like, okay, well, I'm going to stop using, you know, I got to start doing more

00:35:09.200 | stuff with VBA macros and stop doing stuff manually. And again, it was kind of slower for a while.

00:35:14.080 | And particularly like, you know, things like cleaning up that YouTube timestamp thing,

00:35:23.520 | I could have done that manually, you know, and the first 10 times it would be faster to do it

00:35:29.840 | manually. But don't do it manually, right? Because each time you do it manually, you know, you're

00:35:35.680 | missing out on the opportunity to get better at the thing that's going to make you faster. And the

00:35:39.760 | thing about practicing what you think might eventually be the fast way is that those fast

00:35:46.880 | ways accumulate together in kind of these multiplicative ways. And so, you know, I've been

00:35:54.160 | kind of using this approach of always trying to do things the way I suspect would be the fastest if

00:36:01.920 | I was an expert at it. I've been doing that for like 30 years. And now, most people who watch me

00:36:08.560 | work go, wow, you're very fast at doing stuff. You must be really smart. You know, I'm like,

00:36:13.680 | no, I'm not really smart. Like, you should have seen me when I started. I was terrible. But now

00:36:17.600 | these things have all accumulated, right? So, yeah. And if anybody finds, you know, good tutorials,

00:36:26.000 | let me know. Honestly, it's been a long time since I've run a VIM tutorial. So I don't know

00:36:29.600 | if this one's good or bad. This is the first one that came up in Google. But the VIM tutorial is

00:36:35.360 | good. The best tutorial is on Linux in the terminal. If you just type in VIM tutorial

00:36:43.840 | in the terminal, it should pop up a very nice tutorial. And I just wanted to say, Jeremy,

00:36:48.720 | you know, a few minutes of speech that you just gave. It was absolutely wonderful and very, very

00:36:56.720 | useful. Okay, yeah. So here is what happens if you type VIM tutor. And it will teach you exiting VIM.

00:37:03.920 | So lesson one, moving the cursor, lesson two, exiting VIM. So that's a good start. Make sure

00:37:10.320 | caps lock is not depressed. Impress J enough times so that lesson 1.1 fills the screen. J,

00:37:15.280 | J, J, J, J. Okay. So because the VIM tutor is in VIM, it forces you to use VIM, which is good.

00:37:25.600 | And the nice thing about this is, you know, move the cursor to the line below marked blah, blah,

00:37:30.400 | blah. Here it is. Fix the errors. Move the cursor. Okay. So here's a useful one to know. X to cross

00:37:37.920 | out something. So X. There we go. Thanks for that reminder. And the first time you do, you go

00:37:47.280 | through the VIM tutor, it will feel overwhelming. It did to me only after, you know, on like third,

00:37:55.520 | fourth try, does it start to make sense and are able to complete the entire thing. But also,

00:38:00.960 | when I was learning the basics of VIM, I realized that it has a steep learning curve.

00:38:08.720 | And I like to make things appealing, attractive, and simple for me. So I think Dimitri also mentioned

00:38:15.920 | this in the chat here a second ago. There is a game called VIM Adventures, which is in your browser.

00:38:22.160 | And it's another way that you can get exposed to them. That's how I learned it. So I would

00:38:30.640 | dive into a call when I had my corporate job. And instead of, you know, whatever people do on calls,

00:38:39.680 | which is just, I don't know, browser edit, I would do this. And that was my time.

00:38:49.680 | Okay. Now I just tried pressing the arrow keys and VIM to see what the VIM Adventures,

00:38:54.720 | and it says, don't use the arrow keys. I don't agree with that, by the way. A lot of people are

00:39:02.160 | overly purists about, like, you have to do things the VIM way. So, okay, yes, you can use H, J, K,

00:39:10.320 | and L. But seriously, it doesn't matter. Anyway. By the way, I see there's actually just a few

00:39:17.120 | things in the Zoom chat. If you can, please say it out loud. There's a couple of reasons why. The

00:39:24.800 | first is I really enjoy social interaction. Otherwise, I'm kind of sitting in my little

00:39:31.120 | office, you know. And then the second is, of course, for the video, people can hear the

00:39:35.520 | questions. Now, I know sometimes people just can't really talk because they're in some environment,

00:39:39.200 | they can't do it. In that case, if you see somebody asking something in the chat, could you say, oh,

00:39:43.600 | Mike M asked, what key are you pressing to undo, Jeremy? Rather than just answering it in the chat,

00:39:48.320 | and that way I could, like, say that anyway. It looks like, so, yes, somebody said, how did you

00:39:54.320 | do undo? So, the answer is you to undo. Can I suggest one last resource that is quite amazing

00:40:00.800 | for VIM? It's the VIM book, editing at the speed of light. Editing, I don't know that one. Speed.

00:40:10.400 | Speed of thought? Of thought, yes, yes, yes. Practical VIM. That's really, you know,

00:40:18.720 | really well written. And there's a similar book for tmux. So, that's how I

00:40:26.080 | start the books that made the really big difference for me. Now, let me tell you something not to do,

00:40:31.920 | which is don't install lots of plugins. There's lots of plugins you can install.

00:40:37.600 | And, you know, after using VIM for well over 20 years, I don't use any plugins at all.

00:40:45.600 | It's not to say that there are none that are any use. But, like, they're not that useful, honestly.

00:40:58.080 | And you can get lost in that whole, like, customizing things thing. And I just wanted

00:41:04.320 | to make it clear to say, like, actually, out of the box VIM works extremely well.

00:41:09.520 | Now, having said that, I customize it using a VMRC. So, an RC file in Linux and stuff is like,

00:41:19.440 | you know, the normal kind of suffix for configuration files. And I do do some customization

00:41:26.640 | of it. And I actually put all my configuration files in a GitHub repository.

00:41:37.920 | Or .files. And you'll see here there's a VMRC. But it's only 99 lines. And there's things like,

00:41:50.080 | for example, remember, I mentioned that you can jump to the next -- you can jump around Windows

00:41:54.800 | by pressing Ctrl + W. I made it so you can also press backslash W and backslash up and backslash

00:42:04.960 | down. So, just really minor things like that. And also some little things like -- oh, I guess

00:42:15.360 | I do have some things installed. I don't use them anymore. Also some things like Python syntax

00:42:23.280 | highlighting. And also, to be able to see things clearly when you've got a black background with

00:42:34.400 | light text, you have to say set background equals dark. So, I don't know. Little things like that.

00:42:38.880 | It comes with some nice defaults. You can just actually do this source command to get some nice

00:42:43.280 | defaults. >> Quick question, please. Is this one public or private?

00:42:50.720 | >> Everything of mine is public. >> Fantastic. Thank you.

00:42:54.160 | >> Pretty much, I think. >> I have a question. What are your thoughts

00:42:59.600 | about Visual Studio Code to edit files? >> They're great. I just talked about it.

00:43:05.600 | Yeah, I said it's really good. Yep. I like Visual Studio Code.

00:43:09.760 | >> Hi, Jeremy. Do you suggest using Vim key bindings for Jupyter and VS Code as well?

00:43:19.280 | >> I don't. Because I find it's not about the key bindings. It's about the numbers and the

00:43:26.400 | motions and the dots and the macros and like that stuff. And I don't find that there are other

00:43:33.280 | editors that Vim as well as Vim do. So, when I use VS Code, I rather, you know, like fully inhabit

00:43:41.760 | the VS Code world. And so, I use the normal VS Code key bindings and try to learn to use VS Code

00:43:47.200 | as well as I can. So, yeah, I don't do that. Sometimes I've tried. And I'm always disappointed.

00:43:58.720 | It's always like, yeah, it's not really. So, VS Code is great at being VS Code. And I would use that

00:44:09.040 | for editing a big markdown file maybe. I don't use it much. But I guess if I was working with HTML

00:44:26.080 | or CSS or something, I feel like the way it kind of handles those kind of file formats is really

00:44:31.520 | nice. You can set up Vim to be really nice as well. But VS Code works a bit better, more out of

00:44:38.400 | the box, I suppose. Yeah, and also for like navigating through a large repository, VS Code

00:44:46.000 | can be a bit easier to use maybe. To ask whether you could use a fairly large project with

00:44:56.160 | multiple files and whether it was doable via Vim. Yeah, it's definitely doable via Vim.

00:45:06.240 | Yeah, I mean, we can take a look if you're interested. So, yeah, let's take a look.

00:45:11.040 | Actually, it is useful to know how to do this. So, let's take, for example, the fast AI repo.

00:45:15.680 | Okay. So, let's clone it.

00:45:23.600 | And so, let's do it all in paper space. Now, in paper space,

00:45:34.080 | the /notebooks directory is persistent across machines. So, it probably makes sense to clone

00:45:46.000 | this into the /notebooks directory. So, if I open up my terminal, so it's persistent within a machine

00:45:54.640 | and it's persistent across restart. So, if I get clone here, it'll still be on this machine.

00:46:03.120 | Next time I open it, because that's what /notebooks is. It's persistent across restarts on one machine.

00:46:08.800 | Quick question, Jeremy. Yeah, actually, just before you do, I'm just going to cancel this and mention

00:46:15.440 | some a little shortcut if that's okay. Did you see that was taking a really long time to clone?

00:46:20.560 | The reason why is it's cloning every single version of fast AI that's ever existed. And since I don't

00:46:27.840 | need every single version, if you type --depth1, it'll just give you the most recent version that

00:46:35.440 | will save some time. So, yeah. So, go ahead. One of the other scripts you had, you were bringing

00:46:42.720 | in /notebooks from storage, like storage somewhere. Is that a change? Yeah, I didn't really understand

00:46:51.440 | how /notebooks persistence worked at that point. I hadn't spent enough time reading the docs.

00:46:56.880 | Yeah. So, let's pretend that never happened. Okay. So, now that I've cloned this into /notebooks,

00:47:02.720 | you can see it's appeared, right? Because this is where Jupyter is running from.

00:47:06.080 | So, fast AI is what's called an nb-dev project, which means it's all developed in notebooks. So,

00:47:14.160 | these are the notebooks which create fast AI. And then those all get exported as Python modules

00:47:23.280 | into here. It's not a very interesting one. And as you can see, it says, "Oh, don't edit me.

00:47:33.120 | Edit the notebook." That's fine. Okay. Now, if you want to explore through a code base,

00:47:45.120 | it's really helpful to be able to, like, click on symbols and jump to their definitions and then

00:47:50.560 | jump back again to kind of see how it all works. And so, you can actually do that on GitHub,

00:47:57.680 | by the way. I don't know if you've noticed this, but it's quite neat.

00:48:02.000 | So, for example,

00:48:05.920 | to detach, if I click on it.

00:48:11.680 | Oh, it's interesting. It doesn't know how to find that one. It's not perfect.

00:48:19.520 | That one's actually from PyTorch. That must be something it knows how to find.

00:48:23.760 | What about this one?

00:48:27.120 | A popular model, maybe?

00:48:30.000 | Well, it's fine.

00:48:31.360 | Yeah, it's a popular model. Okay. Well, this is very strange.

00:48:37.840 | In theory, it would. Finally, it found one. Okay. So, one problem with doing it in GitHub is it's

00:48:49.600 | not particularly good at it. But, yeah. So, Vim can also do that, as can VS Code. And VS Code and Vim

00:49:00.000 | both rely on something called C tags to do that. C tags is a project to create an index

00:49:08.800 | of the symbols that are in your program.

00:49:14.640 | So, we want to install that.

00:49:28.240 | I actually haven't bothered Googling it for like 20 years, so I didn't realize that

00:49:36.480 | the thing I am used to using has been updated to this new thing.

00:49:39.600 | So, that's interesting.

00:49:43.360 | I guess I should try using it. So, Ubuntu, install, universal C tags.

00:49:52.000 | Oh, God, snap. I don't like snap.

00:49:56.080 | Well, I guess I can if I have to.

00:50:04.240 | Actually, I tell you what I normally do for installing things is I like to find out if

00:50:08.880 | there's a Conda installer. Because that makes life very easy. And there is. There's a universal C

00:50:15.360 | tags. Okay. That's handy. Universal C tags. So, Mamba, install, universal C tags.

00:50:26.320 | And this is one of the really cool things about Conda and Mamba is that I can install.

00:50:31.840 | Ah, well, we don't have Mamba installed. That's fine.

00:50:36.880 | We can set that up.

00:50:39.840 | Conda, install, minus C, defaults, minus C, Conda, forge, Mamba.

00:50:50.960 | And so, in some future lesson, we'll talk about how to get these Conda and Mamba installed things

00:50:57.840 | working persistently in paper space. There's probably some way to do it in snap as well.

00:51:10.960 | I've never bothered checking. I don't know if anybody knows Ubuntu, snap, install, home directory.

00:51:16.560 | I wonder if that's possible. This thing that Jeremy is going to show us,

00:51:23.840 | this will give us superpowers. This is one of my favorite features of them and of

00:51:32.000 | just jumping into them whenever I'm browsing through any code on the next, in a team like Spain.

00:51:39.200 | And this is the way that professional developers interact with code. And it's not even all the

00:51:47.360 | professional developers. So, like, you know, the ones who, like, limited view. Very few people

00:51:55.360 | can navigate around code that quickly. And I think that really makes an enormous difference.

00:52:01.520 | So, whenever Jeremy covers this, I become excited. And, you know.

00:52:06.480 | That's great. We're lucky getting excited, Radek.

00:52:13.120 | Okay. So, there's Mamba. So, we can never remember. Install.

00:52:20.960 | Oh, I'll just press up here a couple of times. Universal C tags.

00:52:25.840 | Oh, and we don't. Okay. So, we're not using Mamba Forge here. We should probably, I might

00:52:32.880 | ask paper space if they can switch to using Mamba Forge so we don't have to worry about

00:52:36.880 | this in the future. But for now, we'll have to put, it's from the Conda Forge channel.

00:52:42.240 | Because the one that they've got installed does not use Conda Forge by default.

00:52:50.080 | I might also talk to them about making it so that Python 3.9 is the default,

00:53:09.120 | since it's still using 3.7, as we saw last time.

00:53:12.720 | All right. So, if we CD into the first AI directory, there's a bunch of Python code we

00:53:28.560 | want to look through. So, if you type C tags, that's the program that creates the index that

00:53:36.640 | we want. And to run it recursively on the current folder, most things in Linux and stuff for capital

00:53:45.280 | R for recursive and then dot means the current folder. So, that's indexed the current folder

00:53:52.000 | and it's created. I expected it to create a file called C tags. I wonder if it's changed how this

00:54:03.360 | works. Sorry, it's created a file called tags. So, it's created this file here called tags.

00:54:10.400 | And if you look at it, you're basically, it's just a whole list of like symbols that it found in my

00:54:16.480 | code and regexes to find where they are and what file it came from. You don't ever have to look at

00:54:21.360 | that. The key thing to know is now we can jump straight to a tag. So, for example, if we want to

00:54:29.200 | open up the array mask, whatever file defines array mask and put it in the right place, I can type

00:54:38.560 | vim minus t for vim jump to a tag and type array mask and that will jump straight to the definition.

00:54:46.080 | Okay. So, that's one way to do it. Another way to do it would be, let's say we were looking

00:54:53.040 | at something else like layers.py, is you can type tag jump and then type ar tab and then it'll list

00:55:06.560 | all the things that match and then I can hit enter and that will jump to that tag.

00:55:12.640 | Another thing that you can do is you can notice, for example, this is inheriting from array image

00:55:22.640 | base to jump to the definition of array image base. It's control right square bracket and so

00:55:30.720 | when I hit that, it jumps to that definition and then to go back to the previous tag, it's control

00:55:36.080 | t for tag. Okay. So, they're the key ways to jump around. Okay. So, for example, if we wanted to find

00:55:44.960 | out some tabular class, I could go tab, tag jump, now start typing tabular and hit tab and here's

00:55:51.280 | my various tabular classes. Go to tabular colab. Okay. So, tabular colab is defined in two places.

00:56:00.240 | Now, that's annoying. One is it's in an ipy check points, which is the backups. So, this is where

00:56:07.360 | you would actually create a c tags config file telling it to ignore anything inside ipy'd nb

00:56:15.280 | check points because you never want to go to the backup version. So, for now, it's confused about

00:56:19.040 | which one I want. So, I'll hit two to go to the non-confusing one and there you go.

00:56:24.160 | Any other tricks you know with tags, Radik? >> Yeah. Just wanted to mention one and this is

00:56:39.120 | what I did only once or twice because I'm always too lazy to set it up. But there is some way,

00:56:46.400 | like with the fastai code here. So, you know that it's using PyTorch a lot. And sometimes you would

00:56:55.600 | be editing a fastai file, but you would like to jump to the definition of some functionality

00:57:02.640 | in the PyTorch code base. >> Oh, yes. That's a good one.

00:57:06.880 | >> That's very helpful, especially for, you know, if you're just starting with PyTorch,

00:57:14.320 | starting out, it's so much nicer than using their documentation on their website, which is slow and,

00:57:21.840 | you know, you have to still search for it. But, yeah.

00:57:24.960 | >> Yeah. So, you know, maybe in the future we can try setting that up as well. So, yeah,

00:57:30.800 | you can set it up so that these tag jumps can jump into the PyTorch source code as well as the fastai

00:57:38.000 | source code. I'll just show you one more trick, which is if I wanted to look up to find out how

00:57:42.080 | data loaders worked, but I want to be able to see Colab data loaders at the same time, then

00:57:47.360 | hitting write square bracket isn't quite ideal because I've now lost what I was looking at.

00:57:54.160 | So, instead, if you type s tag, that means split tag, and I can start typing data loaders,

00:58:04.160 | then that will split the window and jump to the tag so I can now see the two things that I'm doing.

00:58:12.560 | Which I find handy. Anyway, there's a lot more stuff you can do with this,

00:58:16.240 | but hopefully you've got a sense of, like, yeah, this seems worth investing time in because

00:58:22.000 | here are some things that I didn't know how to do before and might be helpful.

00:58:25.680 | >> Just on the split again, Jeremy, my tab closed down when I pressed command W.

00:58:34.320 | >> Yes.

00:58:35.040 | >> To move around. How did you -- how would you do that within the Chrome browser again?

00:58:40.320 | >> So --

00:58:42.320 | >> Between Windows.

00:58:44.160 | >> On a Mac it's fine because control and command are different, so you can just control W does work.

00:58:50.720 | >> I already do. On the Mac.

00:58:53.840 | >> On the Mac. On Windows, if you use my .files, maybe we can, in some future one,

00:59:02.480 | we'll learn about my .files, but in my .files I set up, and so if you make this your Vmrc,

00:59:09.600 | then basically you can hit backslash up and backslash down to go up and down a split.

00:59:14.560 | Because I think this C W -- this means control W will be sent to Vm rather than the browser,

00:59:23.120 | so I think that should work fine. Great. All right.

00:59:31.200 | Nice to see you all again. Have fun with Vm.

00:59:37.840 | Tell us if you find any cool tricks on the forum. And I'll see you next time.

00:59:45.040 | >> Cool. Thanks, Jeremy.

00:59:47.120 | >> Thanks, Jeremy.

00:59:47.760 | >> Thank you. Thanks, Jeremy. Bye, everyone.

00:59:49.760 | >> Thanks a lot.

00:59:50.640 | >> Thank you.

Live coding 5

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