WEBVTT 00:00:00.001 --> 00:00:04.060 Hello and welcome to Python Bytes, where we deliver Python news and headlines directly to 00:00:04.060 --> 00:00:10.860 your earbuds. This is episode 179, recorded April 21st, 2020. I'm Michael Kennedy. 00:00:10.860 --> 00:00:11.820 And I'm Brian Okken. 00:00:11.820 --> 00:00:17.340 And Brian, I'm super honored to have Guido von Rossum on the show. Guido, welcome to Python Bytes. 00:00:17.340 --> 00:00:18.840 Hello, glad to be here. 00:00:18.840 --> 00:00:23.020 Yeah, it's really great to have you here. It's going to be wonderful to hear your opinion, 00:00:23.020 --> 00:00:26.820 your perspective on some of these things that we're sharing this week. So welcome to the show. 00:00:26.820 --> 00:00:30.680 All right. And this episode is brought to you by Datadog. Check them out at pythonbytes.fm 00:00:30.680 --> 00:00:34.580 slash Datadog. More on that later. Brian, what do you got? What's up first? 00:00:34.580 --> 00:00:38.800 Well, I've been thinking a lot about community lately, actually. And one of the things that 00:00:38.800 --> 00:00:44.660 came out recently, this was a little bit ago, but it's still fairly new, is the Django project 00:00:44.660 --> 00:00:49.600 announced a new governance model. It's been going on. I mean, I think they've been working on it for 00:00:49.600 --> 00:00:56.080 a couple of years since at least 2018. Some of the specifics are interesting. They had like a core 00:00:56.080 --> 00:01:01.700 team that they dissolved the core team and they mainly kind of have a new role called a merger 00:01:01.700 --> 00:01:07.840 person, which they have commit access, but they only merge pull requests. So most of the changes 00:01:07.840 --> 00:01:14.380 could happen in the pull requests and the discussion that happens there. There is a technical board also 00:01:14.380 --> 00:01:20.980 that was kept to kind of make some technical decisions if it's necessary, but apparently it hasn't 00:01:20.980 --> 00:01:26.220 been necessary for a while. I think it's interesting that they switched the governance model midstream. 00:01:26.220 --> 00:01:32.580 And then also the rationale around it, I think is interesting. And the rationale is around trying 00:01:32.580 --> 00:01:38.440 to get more people contributing to it. So they had like their core team and that hadn't really changed 00:01:38.440 --> 00:01:44.040 for a long time. And people that were set up as core people really weren't contributing much anymore. 00:01:44.600 --> 00:01:50.340 Anyway, I just thought that was interesting that they, the reason around changing the governance was 00:01:50.340 --> 00:01:52.620 around trying to get new people in. 00:01:52.620 --> 00:01:57.020 Yeah, I think that's a great idea because, you know, Django has been around for a long time and it's a 00:01:57.020 --> 00:02:01.680 fairly stable project. So I think it's kind of hard to jump in. I mean, it's a little bit like Python 00:02:01.680 --> 00:02:02.540 itself, Weido. 00:02:02.840 --> 00:02:09.820 Right. I'm thinking that sort of maybe five years in the future, Python could consider a similar move 00:02:09.820 --> 00:02:15.580 or maybe we'll know that this was not the right move by then from Django's experience. And of course, 00:02:15.580 --> 00:02:22.540 the situation for the two projects is somewhat different, but we definitely also feel the pain 00:02:22.540 --> 00:02:30.900 of sort of not getting enough new contributors. But we only fairly recently, like early last year, 00:02:30.900 --> 00:02:36.960 we changed our governance structure completely. So it's a little early to start considering changing 00:02:36.960 --> 00:02:37.880 it again, probably. 00:02:37.880 --> 00:02:42.820 Right. Of course, we're just starting to see the outcome of the decisions and the releases that 00:02:42.820 --> 00:02:44.220 are actually going through that model, right? 00:02:44.220 --> 00:02:49.780 Yeah. I've been working with the steering council model for say 16 months now. 00:02:49.780 --> 00:02:52.800 Yeah, I guess so. 3.8 definitely came out under that model. 00:02:52.800 --> 00:02:53.540 Yeah. 00:02:53.540 --> 00:02:57.740 The thing that Python did, I think is kind of interesting. And I don't know if you started it, 00:02:57.740 --> 00:03:04.360 but the notion of having more core mentors to try to mentor new core developers, I think that's an 00:03:04.360 --> 00:03:10.020 interesting thing that you can't really like make people be mentors, but that's an interesting way to 00:03:10.020 --> 00:03:11.440 get more core developers on. 00:03:11.440 --> 00:03:17.520 We have a few people who are very active as mentors, in addition to being active as core devs. 00:03:17.680 --> 00:03:19.680 And it really does make a difference. 00:03:19.680 --> 00:03:20.560 Yeah. 00:03:20.560 --> 00:03:20.860 Yeah. 00:03:20.860 --> 00:03:27.060 We don't have enough mentors to mentor everyone who wants to become a core dev. 00:03:27.060 --> 00:03:31.940 Yeah. Yeah. So I think that's really great. I mean, it's one thing to write web apps in Django 00:03:31.940 --> 00:03:38.400 or to write Python code. It's an entirely different thing to write Django or write Python, right? 00:03:38.400 --> 00:03:43.440 It's a very different skill set. And so I think that mentor model is really a great bridge. 00:03:43.580 --> 00:03:48.900 Yeah. So speaking of things, I think are going to be really helpful, but in a much simpler way, 00:03:48.900 --> 00:03:55.020 this is sort of a data science topic for everyone out there. And one of the problems in data science 00:03:55.020 --> 00:04:01.860 is you can end up with very large data sets, complicated data, but every now and then there 00:04:01.860 --> 00:04:07.400 might be a none where you expected an integer, or there might be a empty string where you expected 00:04:07.400 --> 00:04:13.720 a date or something like that. And understanding how that data is for how completed it is, where 00:04:13.720 --> 00:04:19.820 is it more incomplete than less complete, right? Or less, more or less, and so on. So there's this 00:04:19.820 --> 00:04:25.080 cool project called missing no, which I think is missing number, right? Shortened. And the idea is 00:04:25.080 --> 00:04:31.280 it's a missing data visualization module for Python. And you too can see the picture in the show notes and 00:04:31.280 --> 00:04:37.060 folks who listen to this, they can go back and see it in the show notes as well. But it's a really cool 00:04:37.060 --> 00:04:41.940 and simple little library, but it's not just show me a quick graph. It actually does some pretty 00:04:41.940 --> 00:04:47.760 powerful analysis. So what you can do is if you've got like some pandas data, you can just go to it and 00:04:47.760 --> 00:04:53.640 say msno.matrix and give it a sample of your data. And it gives you these really cool graphs of like 00:04:53.640 --> 00:04:59.540 vertical, either black or white bars or bars that are like kind of zebra stripe, depending on whether or not 00:04:59.540 --> 00:05:05.540 there's missing data. It shows you which parts, which columns are more complete or incomplete. 00:05:05.540 --> 00:05:12.500 And even as a little graph on the side, that tells you the likelihood or the correlation of a row being 00:05:12.500 --> 00:05:17.380 incomplete, right? Like you might have a missing address on one line, but in another one has a missing 00:05:17.380 --> 00:05:21.540 phone number, or it could be more likely that those are both missing at the same time. There's like a 00:05:21.540 --> 00:05:23.960 little graph to visualize that kind of stuff. What do you guys think? 00:05:24.100 --> 00:05:32.580 I think it's very cool. I'm not a data anything person myself. So yeah, to indicate how much I am 00:05:32.580 --> 00:05:39.060 not in the target audience for this module. The whole time I read your modules, I had the grouping 00:05:39.060 --> 00:05:47.280 wrong. I thought it was the missing data visualization module. And I thought, well, that's kind of cool that 00:05:47.280 --> 00:05:53.200 that they're sort of, they say there's something missing. And this clearly is the one that now it's 00:05:53.200 --> 00:05:59.600 turned up, but it's actually visualizing missing data, which actually I understand what that is. I've seen 00:05:59.600 --> 00:06:07.280 a spreadsheet or two, and I can actually even understand the little example chart that you pasted into 00:06:07.280 --> 00:06:12.240 through the notes without understanding anything else around it. 00:06:12.240 --> 00:06:16.320 Yeah, it's so wonderful because that's why I actually think I like this and I chose it as you 00:06:16.320 --> 00:06:20.240 could just look at that picture and go, oh, I basically get a sense for what this data is like. 00:06:20.240 --> 00:06:25.600 It's complete. It's not complete. It's mostly incomplete on this column or whatever. And yeah, 00:06:25.600 --> 00:06:31.920 it's really nice. And I suspect you could, if you had data, say, in like a database or a file or 00:06:31.920 --> 00:06:35.360 something, you could probably just read that into a pandas data frame and then throw it out here and 00:06:35.360 --> 00:06:39.360 visualize like database missing data or file missing data or whatever. But it's really nice. 00:06:39.360 --> 00:06:43.680 Yeah. For large data sets, one of the things you got to do is to decide when you're cleaning it up, 00:06:43.680 --> 00:06:48.400 what to do with the missing data. And there's, I mean, there's some nones or whatever. There's some 00:06:48.400 --> 00:06:56.080 strategies to either fill it in with interleaved data or something or, or just throw those rows 00:06:56.080 --> 00:07:00.720 completely away. But you, I mean, you don't really know how much data you're throwing away if you, 00:07:00.720 --> 00:07:04.480 without visualizing it. So this is pretty cool. I think this is great. 00:07:04.480 --> 00:07:08.800 Yeah. And it has other visualizations as well. It has heat maps, which are like correlations, 00:07:08.800 --> 00:07:13.200 you know, so like address and phone number correlated kind of things I was talking about. 00:07:13.200 --> 00:07:19.200 It has bar charts and the most interesting or unique visualization is the dendogram, 00:07:19.200 --> 00:07:23.760 which I had never heard of, but this is the hierarchical clustering algorithm from SciPy actually. 00:07:23.760 --> 00:07:30.320 And it creates this kind of like hierarchical tree of relationships of missing data. 00:07:30.320 --> 00:07:34.160 There's just, if you are worried about like cleaning up data or stuff like that, 00:07:34.160 --> 00:07:38.160 or visualizing how good your data is, you could throw it at this real quick and get some great 00:07:38.160 --> 00:07:38.480 answers. 00:07:38.480 --> 00:07:39.440 Yeah, that's cool. 00:07:39.440 --> 00:07:44.160 Yeah. All right. Well, Guido, you have been busy with the language summit recently, right? 00:07:44.160 --> 00:07:45.040 What's the news there? 00:07:45.040 --> 00:07:52.720 Yes. Well, normally the language summit basically is in-person meeting where about 50 people who are 00:07:52.720 --> 00:07:59.360 mostly, but not exclusively core devs get together a day or two before the actual Python conference. 00:07:59.360 --> 00:08:01.760 Since the conference was canceled. 00:08:01.760 --> 00:08:03.840 This would have been in Pittsburgh, right? 00:08:03.840 --> 00:08:06.480 It would have been in Pittsburgh this year, right? 00:08:06.480 --> 00:08:10.640 Obviously the conference was canceled and the language summit was two. 00:08:10.640 --> 00:08:16.000 And then the two organizers thought, well, okay, this sounds like the kind of meeting that we can 00:08:16.000 --> 00:08:21.760 actually try to do on Zoom. You can't have a whole conference on Zoom, but you can probably have a 00:08:21.760 --> 00:08:28.960 meeting with 50 people on Zoom. And they tweaked the format a bit so that, I mean, you can't be on 00:08:28.960 --> 00:08:36.240 Zoom for an entire day. I find Zoom incredibly intense. And after an hour of Zooming, 00:08:36.240 --> 00:08:38.960 I'm usually ready for a break. 00:08:38.960 --> 00:08:41.760 Yeah. All the virtual stuff takes a lot more attention. Yeah. 00:08:41.760 --> 00:08:50.560 Yeah. User interface sucks. Privacy probably sucks, but it clearly serves its purpose. So we had it 00:08:50.560 --> 00:08:56.480 spread over two different days. And then in addition, because nobody was traveling to Pittsburgh, 00:08:56.480 --> 00:09:03.600 we spread it out in time. One day it was really early for me so that we could also have participants from 00:09:03.600 --> 00:09:10.480 Europe. And one day it was really late for me so that we could have some people from Australia join us. 00:09:10.480 --> 00:09:18.320 One of the organizers lives in Poland and he was there till the end on both days. So I didn't, I don't know. 00:09:18.320 --> 00:09:21.040 That's commitment. 00:09:21.040 --> 00:09:27.600 So as usual, the format wasn't actually all that different. It's typically like half hour slots for 00:09:27.600 --> 00:09:36.800 various topics that are important to either get information to core devs and usually also get 00:09:36.800 --> 00:09:43.040 feedback from core devs. And we pretty much stuck to that format. The one big thing that you miss, 00:09:43.040 --> 00:09:49.040 of course, is all the whispering to the guy who was sitting next to you or during the break, 00:09:49.040 --> 00:09:53.760 quickly grabbing three other people and having a little huddle about a topic. 00:09:53.760 --> 00:09:56.560 Yeah. That's what's so powerful about in-person conferences. 00:09:56.560 --> 00:10:04.160 Yeah. We missed the entire hallway track, but it was still good to have sort of short presentations and 00:10:04.160 --> 00:10:11.040 Q&A sessions. And the Q&A sessions actually worked really well. There was a little tool that you can 00:10:11.040 --> 00:10:19.200 use to sort of moderate questions. And Lukasz was like running the moderation tool and nobody was asking 00:10:19.200 --> 00:10:23.760 spam questions. So all he had to do was just click OK for every question, I think. 00:10:23.760 --> 00:10:31.520 Yeah. That tool is much more structured than the chat channel on Zoom could be. And sort of raising 00:10:31.520 --> 00:10:37.360 your hand on Zoom and waving doesn't really work if there are 50 people, because there's no way to see 00:10:37.360 --> 00:10:39.920 more than 16 people or so at a time. Yeah. 00:10:39.920 --> 00:10:47.440 So anyway, the first day, each day, there were like maybe five topics and a few miscellaneous things. 00:10:47.440 --> 00:10:53.200 Shall I just go over each day briefly, see if I can sort of run them all off? 00:10:53.200 --> 00:10:58.800 Yeah, I would say just maybe touch really quickly on just the things that you felt like really might 00:10:58.800 --> 00:11:01.120 make an impact going forward, potentially. 00:11:01.120 --> 00:11:08.560 Just a one-liner guy who originally implemented f-strings gave a talk about whether maybe all 00:11:08.560 --> 00:11:16.400 strings should become f-strings. And the general sentiment was that that would have been nice 00:11:16.400 --> 00:11:21.280 in Python 1.0 or so, but there is no way that it would just break too much code. 00:11:21.280 --> 00:11:25.440 It's going to break too much. I totally hear that though, because I'm so often I'm typing in a 00:11:25.440 --> 00:11:29.680 string. I'm like, oh, I need to put a variable here, but I've typed 20 characters in that I got 00:11:29.680 --> 00:11:33.360 to go back to the beginning, but not the beginning of the line, because maybe that's what I got to get 00:11:33.360 --> 00:11:37.280 to the beginning of the string and then go. Maybe we could even put the F at the end. Who knows? 00:11:37.280 --> 00:11:41.360 But yeah, I would love to see it. But it's I totally understand. You can't do that without 00:11:41.360 --> 00:11:45.120 breaking stuff. There are downsides to automatically doing it, too, because 00:11:45.120 --> 00:11:50.000 curly braces are useful for all sorts of things besides formatting. 00:11:50.000 --> 00:12:05.920 So that was sort of the opening salvo. Then my two co-conspirators on the peg parsing project gave a talk about how we're going to hopefully introduce a new parser in Python 3.9. 00:12:06.880 --> 00:12:11.520 And we've been coding for like almost a year now, probably. 00:12:11.760 --> 00:12:18.980 It started out as a little hobby project of mine and gradually became more serious and more people started helping out. 00:12:18.980 --> 00:12:26.880 And the last few months, we've been doing heavy engineering work to actually prepare for the integration. 00:12:26.880 --> 00:12:29.480 But we didn't have steering council approval yet. 00:12:29.640 --> 00:12:43.140 We made it a PEP and we sort of said, well, this is a nice thing, but we're not going to do this unless there is sort of clear consensus or at least general agreement that we are going to do this. 00:12:43.140 --> 00:12:53.020 And so very soon after the summit, the steering council actually had a meeting and approved a bunch of peps and ours was one of them. 00:12:53.020 --> 00:13:01.720 And then the last two days, I've been stressing out because we wanted to get the new parser in the alpha 6 release, which is going out tomorrow. 00:13:01.720 --> 00:13:08.840 And so we're now in the last, the very last stretches of preparing for alpha 6. 00:13:08.840 --> 00:13:15.940 And we're just deleting or disabling tests that are still failing that we know how to fix them, but we just don't have the time. 00:13:16.100 --> 00:13:18.580 Right. That's exciting that this project is going to be in there. That's great. 00:13:18.580 --> 00:13:23.520 Yeah. So that's the new parser. And if all goes well, nobody will notice a thing. 00:13:23.520 --> 00:13:24.360 Ideally. 00:13:24.360 --> 00:13:29.300 What are the effects? Is it going to speed things up or make things more maintainable? 00:13:29.300 --> 00:13:42.200 It's going to sort of open up the grammar for future changes to the language that we currently can't do because the old LL1 parser holds us back. 00:13:42.200 --> 00:13:42.540 Okay. 00:13:42.540 --> 00:13:45.940 That's sort of the main motivation. 00:13:45.940 --> 00:13:46.300 Super. 00:13:46.300 --> 00:14:02.260 There was one interesting talk about something called HPy, which is a proposal for a new, more portable API and in particular focused on other Python implementations besides CPython. 00:14:02.260 --> 00:14:09.780 As you may know, PyPy has been struggling for over a decade with compatibility with extension modules. 00:14:10.180 --> 00:14:18.680 And the HPy proposal is basically instead of pointers to objects, you have handles, which is a pointer to a pointer to an object. 00:14:19.280 --> 00:14:28.380 And there's a whole API around handles that is equivalent to the existing API, but it allows different styles of garbage collection. 00:14:28.380 --> 00:14:34.240 For example, you could implement a garbage collector that moves objects behind your back occasionally. 00:14:34.240 --> 00:14:42.440 Right. You might get a generational compacting garbage collector because you could update the value of the pointer pointer without changing the actual pointer. 00:14:42.440 --> 00:14:42.740 Right. 00:14:42.820 --> 00:14:42.960 Yeah. 00:14:42.960 --> 00:14:43.320 Yeah. 00:14:43.320 --> 00:14:43.460 Yeah. 00:14:43.460 --> 00:14:43.620 Yeah. 00:14:43.620 --> 00:14:44.720 That's actually really exciting. 00:14:44.720 --> 00:14:45.100 Yeah. 00:14:45.100 --> 00:14:49.580 And it's still in early stages, I believe, but it looks pretty promising. 00:14:50.380 --> 00:15:01.380 Eric Snow gave a lightning talk about sort of a retrospective of all his work on multi-core support, which is now beginning to conclude. 00:15:01.380 --> 00:15:11.640 Well, maybe it's too soon to call it the conclusion, but we're going to have sub-interpreters with a much better API, either in 3.9 or in 3.10. 00:15:11.640 --> 00:15:23.680 There's a PEP around that 5.5.4, which will definitely be moving forward, but whether it's considered mature enough to land in 3.9 is not entirely clear. 00:15:23.680 --> 00:15:24.020 Yeah. 00:15:24.020 --> 00:15:25.840 Eric's work is very interesting there. 00:15:25.840 --> 00:15:26.040 Yeah. 00:15:26.040 --> 00:15:26.480 Yeah. 00:15:26.480 --> 00:15:31.600 And in 3.10, we will probably have separate gills per sub-interpreter. 00:15:31.600 --> 00:15:35.180 That is going to be a major new thing. 00:15:35.180 --> 00:15:35.740 Let's see. 00:15:35.740 --> 00:15:37.140 What else do we have? 00:15:37.580 --> 00:15:43.640 Well, so the next day, I gave a talk about the future of typing, which, oh, yeah, there's one detail. 00:15:43.640 --> 00:15:54.880 You might remember that we introduced something called from-dunder-future-import-annotations, which made it so that annotations are no longer evaluated at runtime. 00:15:54.880 --> 00:16:01.080 You can still introspect them, but you'll just get the string containing the annotation expression back. 00:16:01.080 --> 00:16:05.920 Well, that's going to be the default in 3.9, most likely. 00:16:06.300 --> 00:16:14.240 There's still a little debate about that, but there was like a two-thirds preference for just making that the default in 3.9. 00:16:14.240 --> 00:16:19.800 And various people argued effectively that nobody should notice any difference. 00:16:19.800 --> 00:16:23.680 I'm really excited or happy to have typing in the language. 00:16:23.680 --> 00:16:33.400 It makes such a difference for the right use case, you know, on defining the boundary of APIs or making the editor understand something better when it otherwise wouldn't. 00:16:33.400 --> 00:16:40.820 If you're maintaining tens of thousands of lines of Python code or more, type annotations really make a difference. 00:16:40.820 --> 00:16:41.740 Yeah, for sure. 00:16:41.740 --> 00:16:44.620 I still don't recommend teaching them to beginners, though. 00:16:44.620 --> 00:16:45.120 Oh, really? 00:16:45.120 --> 00:16:45.500 Okay. 00:16:45.500 --> 00:16:47.620 It depends on what kind of beginners you have. 00:16:47.620 --> 00:16:52.580 If they're sort of recuperating Java programmers, maybe you should introduce them. 00:16:52.720 --> 00:16:57.740 But if they're like actually blank slate, this is the first time they're programming ever. 00:16:57.740 --> 00:17:00.500 I wouldn't bother with them with annotations. 00:17:00.500 --> 00:17:00.820 Yeah. 00:17:00.820 --> 00:17:02.060 I kind of agree with that. 00:17:02.060 --> 00:17:02.260 Yeah. 00:17:02.260 --> 00:17:13.320 What's sort of still missing for the data science world is extensions to the type system for NumPy and Pandas and stuff like that. 00:17:13.320 --> 00:17:22.800 There is a design, but there are not enough people with available time to actually implement the design. 00:17:22.960 --> 00:17:30.260 And I'm sure that when you're halfway through implementation, all sorts of interesting issues with the design will prop up. 00:17:30.260 --> 00:17:33.740 So the design is not final until it's been implemented. 00:17:33.740 --> 00:17:34.780 Okay. 00:17:34.780 --> 00:17:36.180 Last two topics. 00:17:36.180 --> 00:17:44.180 Zach Hatfield Dodds gave a very good talk about what he calls property-based testing, 00:17:44.180 --> 00:18:02.600 and which really is about a tool named Hypothesis that introduces testing approach that I think was first developed in academia for Haskell that works in a completely different way than your typical unit test-based testing. 00:18:02.600 --> 00:18:02.960 Right. 00:18:02.960 --> 00:18:05.680 The tool decides, right, instead of examples. 00:18:05.680 --> 00:18:16.640 The tool generates test cases, and I've never played with it myself, but the talk sort of made me very excited to play around with it more. 00:18:16.640 --> 00:18:25.780 And it actually, even though it's a very different approach than unit test or pytest-based testing, it will still integrate with that. 00:18:25.780 --> 00:18:32.220 I mean, you can write a unit test and then put some decorator on top of it that produces test data. 00:18:32.520 --> 00:18:45.480 And Hypothesis has all kinds of really advanced stuff for exploring enormous spaces of possible input data and quickly finding bugs. 00:18:45.480 --> 00:18:52.020 Do you think we'll get to a place where we are able to use Hypothesis for some of the testing for the standard library? 00:18:52.020 --> 00:18:56.640 That was one of the propositions that Zach made. 00:18:56.640 --> 00:18:59.980 I think it's still early for that. 00:18:59.980 --> 00:19:00.420 Okay. 00:19:00.520 --> 00:19:18.040 I think it's much easier to introduce Hypothesis in sort of a new project where you haven't yet written all the code in all the tests than it is to retrofit it in a large, mature, or maybe even somewhat dementing project. 00:19:18.040 --> 00:19:18.380 Yeah. 00:19:18.380 --> 00:19:29.160 I think it'll be a while before we'll have hypothesis-based testing for the standard library, just like it'll be a while before we'll have annotations in the standard library, 00:19:29.160 --> 00:19:34.300 rather than annotations sort of separate from the standard library. 00:19:34.300 --> 00:19:47.040 The last talk I want to highlight, and then I'm really done with this, is also a very good talk by Russell Keith-Magee about the state of Bware and Python for Mobile. 00:19:47.040 --> 00:20:06.020 And one of his suggestions was that we adopt some of his mega patches that he's currently being maintaining for several Python releases that would make Python at least compile out of the box or nearly out of the box for the important mobile platforms. 00:20:06.020 --> 00:20:06.800 That'd be cool. 00:20:06.920 --> 00:20:10.300 Yeah, it'd be so wonderful to have Python as an option for mobile. 00:20:10.300 --> 00:20:13.740 It really would bust open the doors and create even more growth. 00:20:13.740 --> 00:20:22.220 Many people believe that sort of mobile platforms are obviously continuing to grow in importance and to grow in power. 00:20:22.220 --> 00:20:26.760 And we'd be crazy if we didn't support Python on those. 00:20:26.760 --> 00:20:30.200 And it may be very important for Python's very survival. 00:20:30.200 --> 00:20:30.520 Yeah. 00:20:30.520 --> 00:20:31.040 Yeah. 00:20:31.040 --> 00:20:34.880 I saw the Block Swan talk that Russell Keith-Magee gave, and it was compelling. 00:20:34.880 --> 00:20:36.680 He is an amazing speaker, for sure. 00:20:36.680 --> 00:20:37.020 Yeah. 00:20:37.020 --> 00:20:37.640 Yeah, yeah. 00:20:37.640 --> 00:20:38.300 That's what I have. 00:20:38.300 --> 00:20:38.600 Great. 00:20:38.660 --> 00:20:40.000 Thank you so much for that insight. 00:20:40.000 --> 00:20:41.180 That was awesome. 00:20:41.180 --> 00:20:44.060 A lot of people don't get to see the behind the scenes. 00:20:44.060 --> 00:20:45.900 They just see what's announced when it comes out, right? 00:20:45.900 --> 00:20:46.360 Mm-hmm. 00:20:46.360 --> 00:20:48.700 Before we move on, let me tell you about our sponsor, Datadog. 00:20:48.700 --> 00:20:51.780 This episode is brought to you by Datadog. 00:20:51.780 --> 00:20:52.960 So let me ask you a question. 00:20:52.960 --> 00:20:55.700 Do you have an app in production that's slower than you like? 00:20:55.700 --> 00:20:58.620 Is its performance all over the place, sometimes fast, sometimes slow? 00:20:58.620 --> 00:21:00.480 Now, here's the important question. 00:21:00.480 --> 00:21:01.400 Do you know why? 00:21:01.400 --> 00:21:02.900 With Datadog, you will. 00:21:02.900 --> 00:21:08.000 You can troubleshoot your app's performance with Datadog's end-to-end tracing, use detailed flame graphs, 00:21:08.140 --> 00:21:10.660 identify bottlenecks and latency in that finicky app of yours. 00:21:10.660 --> 00:21:13.680 So be the hero that got the app back on track at your company. 00:21:13.680 --> 00:21:17.580 Get started with a free trial over at pythonbytes.fm/Datadog. 00:21:17.580 --> 00:21:19.040 Get a cool t-shirt as well. 00:21:19.040 --> 00:21:22.200 Brian, you've got another one that kind of ties into your first one, right? 00:21:22.200 --> 00:21:24.100 But it's sort of the other side of the coin, maybe? 00:21:24.100 --> 00:21:29.180 I don't know what's been happening in the Python world that you sort of orbit in that might make 00:21:29.180 --> 00:21:30.920 you think about these things, but tell us about it. 00:21:30.920 --> 00:21:36.960 No, I've just been thinking about community and codes of contact and enforcement for codes of 00:21:36.960 --> 00:21:37.400 conduct. 00:21:37.400 --> 00:21:38.640 No reason, really. 00:21:38.640 --> 00:21:40.100 Just kind of an interesting topic. 00:21:40.100 --> 00:21:44.800 One of the things I've been thinking about is, especially when researching this, the codes 00:21:44.800 --> 00:21:48.540 of conduct and enforcement of it and how we treat people. 00:21:48.540 --> 00:21:52.860 I first thought it was really important for open source projects, and it definitely is because 00:21:52.860 --> 00:21:55.940 people have the option to just leave and get out of the project. 00:21:56.100 --> 00:22:01.560 So you really want to treat people well so they stick around and have it be welcoming to 00:22:01.560 --> 00:22:02.020 other people. 00:22:02.020 --> 00:22:04.660 But I don't think industry is really that different. 00:22:04.660 --> 00:22:09.680 I think that people have the ability to just get another job or work on a different project. 00:22:09.680 --> 00:22:12.100 So I think these are important for industry as well. 00:22:12.540 --> 00:22:16.800 I took a look at two sets of codes of conduct and the enforcement of those. 00:22:16.800 --> 00:22:19.500 So the PSF has a code of conduct. 00:22:19.500 --> 00:22:23.800 I'm not going to read them all out, but there's things like being open and being friendly. 00:22:23.800 --> 00:22:28.260 And in there, there's a list of inappropriate behaviors as well that's covered. 00:22:28.600 --> 00:22:33.840 Now, also the Django code of conduct, they also have all of these when you read them, there 00:22:33.840 --> 00:22:36.560 are differences, but when you read them, they kind of sound the same. 00:22:36.560 --> 00:22:44.640 One of the things they highlight in the Django one is be careful with your choice, choice of 00:22:44.640 --> 00:22:50.820 words, including, and they include examples of harassment, speech, and exclusionary behavior 00:22:50.820 --> 00:22:51.860 that's not appropriate. 00:22:51.860 --> 00:22:54.900 One of the big differences I saw was the enforcement. 00:22:54.900 --> 00:23:02.300 So the PSF is a two-third majority vote enforcement sort of thing to make sure if something happens, 00:23:02.300 --> 00:23:05.080 like if they want to kick somebody out or put them on probation or something. 00:23:05.080 --> 00:23:10.580 I think that's really important because if you require 100% majority and somebody who is 00:23:10.580 --> 00:23:15.800 on the team that decides is potentially part of the problem, then what do you do, right? 00:23:15.800 --> 00:23:17.160 It's really tricky. 00:23:17.160 --> 00:23:22.520 I mean, if people are just going to abandon a project, right, you would rather have just a 00:23:22.520 --> 00:23:24.640 strong majority make a decision. 00:23:24.640 --> 00:23:29.540 I also think that PSF has probably got a larger, possibly has a larger working group on this 00:23:29.540 --> 00:23:33.940 and is more, I guess, maybe harder to get a hold of people. 00:23:33.940 --> 00:23:38.620 Maybe it's easier to get a two-thirds than maybe you can't even reach all 100% of the group. 00:23:38.620 --> 00:23:45.280 But anyway, the other interesting difference is the PSF code of conduct seems to, I know it 00:23:45.280 --> 00:23:52.360 does cover online interaction as well as events like the conferences and meetups and stuff. 00:23:52.360 --> 00:24:03.100 But I possibly, at least I think that maybe its focus might be more on events, whereas the Django code of conduct is specifically targeted towards online interactions. 00:24:03.100 --> 00:24:13.180 I would say for the PSF that sort of historically, events were the first place where codes of conduct were introduced. 00:24:13.640 --> 00:24:19.920 But we've been using them for online forums more and more in the past few years. 00:24:19.920 --> 00:24:20.320 Okay. 00:24:20.680 --> 00:24:29.780 One of the interesting things with the Django one is that a single person on the committee can act without collaborating with anybody else. 00:24:29.780 --> 00:24:37.840 If it's an ongoing problem or if there's a threat involved or something, they still have to go through the process of notifying everybody else. 00:24:38.080 --> 00:24:42.540 But there is an interesting thing that one person on the committee can intervene right away. 00:24:42.540 --> 00:24:53.260 I'm not saying one is better than the other, or I just think it's interesting and I think it's important for new projects to think about, not just their code of conduct, but how they're going to enforce it. 00:24:53.360 --> 00:24:54.620 And what the timeline. 00:24:54.620 --> 00:24:57.640 So the Django one also includes some timelines, which is interesting. 00:24:57.640 --> 00:25:11.240 And I would really like to make sure that projects kind of practice, maybe figure out what they're going to do if they need to enact one of these things without, you know, before it becomes a problem, they know what they're going to do. 00:25:11.500 --> 00:25:14.200 Yeah, there's a lot of stuff going on with some projects out there. 00:25:14.200 --> 00:25:18.380 So having a couple of examples and side-by-side comparisons, I think is great. 00:25:18.380 --> 00:25:26.900 I was interested to find out our meetup, like the Python meetup that we started, which is on hold right now, unfortunately, because of the virus and quarantine and stuff. 00:25:26.900 --> 00:25:37.980 But because we were getting support from the Python Software Foundation to help pay for the meetup fees and stuff, we had to list a code of conduct on our meetup page and stuff like that. 00:25:37.980 --> 00:25:39.840 Yeah, that makes a lot of sense, but I didn't realize that. 00:25:39.840 --> 00:25:40.440 Yeah, yeah. 00:25:40.500 --> 00:25:43.260 The PSF has been doing that for a few years now. 00:25:43.260 --> 00:25:44.120 Yeah, that's really great. 00:25:44.120 --> 00:25:45.900 All right, this next one I want to cover. 00:25:45.900 --> 00:25:48.460 It goes back a ways, but I think it's really fun. 00:25:48.460 --> 00:25:53.000 And it's something that also, I think, ties together well with our special guest here. 00:25:53.000 --> 00:25:57.280 And this is an article about myths about indentation. 00:25:57.280 --> 00:26:01.220 And Guido, I picked this one because you were talking about this on Twitter just the other day. 00:26:01.220 --> 00:26:03.280 What was the motivation to throw that out there? 00:26:03.280 --> 00:26:04.520 That is a good question. 00:26:04.520 --> 00:26:10.480 I was just going to volunteer the answer because apparently I had a link to that. 00:26:10.480 --> 00:26:14.940 I had a link to that article on my homepage in some odd corner. 00:26:14.940 --> 00:26:18.440 And I have a very, very sort of ready old homepage. 00:26:18.440 --> 00:26:22.300 It's moved it to GitHub pages, but it looks like web 1.0. 00:26:22.300 --> 00:26:25.460 And because it really is, I just added raw HTML. 00:26:25.720 --> 00:26:26.200 Blinden, right? 00:26:26.200 --> 00:26:26.960 With Netscape, huh? 00:26:26.960 --> 00:26:35.820 So someone reported to me a broken link, which happens like, I don't know, once every four years or so. 00:26:35.820 --> 00:26:38.420 Someone reported a broken link. 00:26:38.420 --> 00:26:40.100 Oh, wait, it wasn't even on my homepage. 00:26:40.100 --> 00:26:44.400 It was on an old blog that I can no longer edit at artema.com. 00:26:44.480 --> 00:26:46.520 I'm very glad that that blog is still online. 00:26:46.520 --> 00:26:57.600 But so because I got the report of the broken link, I decided, oh, I'm sure I can still find on archive.org where that link used to point. 00:26:57.600 --> 00:26:59.580 And sure enough, it was there. 00:26:59.580 --> 00:27:02.840 And I thought, oh, that's actually still a neat little article. 00:27:02.840 --> 00:27:05.660 So I thought, okay, tweet of the day or tweet of the week. 00:27:05.660 --> 00:27:06.280 Yeah, I agree. 00:27:06.340 --> 00:27:07.620 And I think it's interesting as well. 00:27:07.620 --> 00:27:20.680 And just to give you a sense of why it might have disappeared, it was one of those types of sites where the domain or the URL included a tilde username path, like, you know, like used to get in university or whatever way back when. 00:27:20.680 --> 00:27:24.680 So anyway, this one is myths about indentation for Python. 00:27:24.680 --> 00:27:32.120 And for people who come from a C-oriented language, I think Python could come across a little bit funky. 00:27:32.120 --> 00:27:36.100 I actually want to share a little story of just sort of my journey with it. 00:27:36.100 --> 00:27:38.120 And how I came to love this. 00:27:38.120 --> 00:27:43.520 But I think this is really interesting for people having the debate about is significant white space useful? 00:27:43.520 --> 00:27:44.040 Is it weird? 00:27:44.040 --> 00:27:44.540 Is it good? 00:27:44.540 --> 00:27:48.100 I did a ton of C++ and then C# development. 00:27:48.100 --> 00:27:49.920 So it was all, and then JavaScript development. 00:27:49.920 --> 00:27:52.840 It was all about the curly brace languages, lots of symbols. 00:27:52.840 --> 00:27:54.700 And then I came to learn Python. 00:27:54.700 --> 00:27:56.320 And I'd love Python right away. 00:27:56.320 --> 00:27:57.700 But it was weird to me. 00:27:57.700 --> 00:27:58.580 I felt kind of naked. 00:27:58.580 --> 00:28:03.160 Like if I'd write an if statement, I'm like, I need some little parentheses to kind of hold the code in place. 00:28:03.160 --> 00:28:04.320 And why don't they need to be there? 00:28:04.320 --> 00:28:08.500 And I need a curly brace to like say when this block of code is done and whatnot. 00:28:08.500 --> 00:28:10.500 It just took a little bit of getting used to. 00:28:10.500 --> 00:28:12.740 But I knew that it was the right thing for me. 00:28:12.740 --> 00:28:17.740 Because when I went back to work on some older projects, I'm like, why are there symbols everywhere? 00:28:17.740 --> 00:28:19.600 What is all this stuff I have to keep typing? 00:28:19.600 --> 00:28:21.000 This is like a broken language. 00:28:21.000 --> 00:28:26.680 And it just took a couple of weeks for me to like make that switch to feel like it was broken to go back to work in languages. 00:28:26.680 --> 00:28:28.180 And I've been doing for like 10 years. 00:28:28.600 --> 00:28:30.620 So well done with the white space, Guido. 00:28:30.620 --> 00:28:31.080 Thanks. 00:28:31.080 --> 00:28:31.440 Yeah. 00:28:31.440 --> 00:28:34.960 But so let's cover some of the things mentioned really quick in the article. 00:28:34.960 --> 00:28:38.360 One is that white space is significant in Python source code. 00:28:38.360 --> 00:28:41.820 And actually, no, not in general is the answer. 00:28:41.820 --> 00:28:44.380 It's significant on the left. 00:28:44.380 --> 00:28:46.160 Right. 00:28:46.280 --> 00:28:49.160 So as much as you indent stuff, that really means things. 00:28:49.160 --> 00:28:56.000 But between variables, like whether you have like a equals seven or a space equals space seven, doesn't matter. 00:28:56.000 --> 00:28:57.380 You can have tons of spaces in there. 00:28:57.380 --> 00:28:57.520 Right. 00:28:57.520 --> 00:29:01.720 Like any other language of spaces kind of don't matter except for on the left. 00:29:01.720 --> 00:29:03.780 So that's cool. 00:29:03.840 --> 00:29:06.300 And also the amount of indentation doesn't really matter. 00:29:06.300 --> 00:29:06.820 Right. 00:29:06.820 --> 00:29:13.040 You could have five spaces or any code suite that you want, or you could have 18 or you could go with a standard four. 00:29:13.040 --> 00:29:14.880 I recommend the four, but you know. 00:29:14.880 --> 00:29:25.560 And then also, if you have something that defines like a list comprehension or an array creation or a dictionary, then all of a sudden the spacing doesn't matter anymore. 00:29:25.560 --> 00:29:25.940 Right. 00:29:25.940 --> 00:29:30.920 As soon as you have like an open square bracket and then you have a bunch of stuff and then close square bracket spacing doesn't matter in there. 00:29:30.920 --> 00:29:35.460 So I think this is interesting to think about as folks debate that maybe within their teams. 00:29:35.460 --> 00:29:39.180 It also, you could say it forces you to use a certain indentation style. 00:29:39.180 --> 00:29:40.520 Well, yes and no. 00:29:40.520 --> 00:29:54.240 If you wanted to write it single statement per line, then yeah, there's a cool example that they gave in the article is like if one plus one equals two, then new line print food, new line print bar, new line print, or just say X equals 42. 00:29:54.240 --> 00:29:57.200 You can also put them on multiple lines with semicolons. 00:29:57.200 --> 00:29:59.920 If you're really missing your semicolons from your language, you could do that. 00:30:00.560 --> 00:30:07.100 The thing that's interesting here, I think this is probably the most significant part of this article or this write-up is if you look at it, it looks right. 00:30:07.100 --> 00:30:09.840 And when it gets parsed, it is right. 00:30:09.840 --> 00:30:18.100 There's an example of some C code that looks visually wrong because it's intended differently, but it's going to parse. 00:30:18.500 --> 00:30:23.080 But the way you see it when you read it is not what's actually happening. 00:30:23.080 --> 00:30:25.020 And I think there was a problem like this. 00:30:25.020 --> 00:30:31.220 Well, I think it was in some, you know, Objective-C or something with Apple in there. 00:30:31.220 --> 00:30:32.660 It was really bad. 00:30:32.660 --> 00:30:35.240 There was an infamous Apple vulnerability. 00:30:35.680 --> 00:30:44.420 I think it might even have been on the iPhone where someone had added a second statement to a block, but it wasn't a block because there were no curlies. 00:30:44.420 --> 00:30:45.100 Right. 00:30:45.100 --> 00:30:50.820 Then it started out with a single conditional line, like if something indent, do the thing. 00:30:51.420 --> 00:30:54.280 And then they just indented, but they didn't put the curly braces in. 00:30:54.280 --> 00:31:01.700 And it was, yeah, it was, it took so long for people to find it because visually it looked like what Python would look actually mean. 00:31:01.700 --> 00:31:01.900 Right. 00:31:01.900 --> 00:31:06.480 It looked like those two things are part of the if block, but because the white space didn't matter, it actually didn't. 00:31:06.540 --> 00:31:08.100 And so that's really interesting. 00:31:08.100 --> 00:31:09.580 I'm not going to go through everything. 00:31:09.580 --> 00:31:10.700 I'll put it in the show notes. 00:31:10.700 --> 00:31:13.240 But another one that I thought is like, I just don't like it. 00:31:13.240 --> 00:31:13.800 And that's fine. 00:31:13.800 --> 00:31:16.700 People can not like it, but it has a lot of advantages. 00:31:16.700 --> 00:31:21.420 Like in that example before, if you had that wrongly indented Python code, it would not parse. 00:31:21.420 --> 00:31:25.580 It's an error to have it not look right and rather than just not be right. 00:31:25.580 --> 00:31:31.780 So it has a lot of advantages and people can really quickly get used to not having to write all those symbols. 00:31:31.780 --> 00:31:34.360 And then you go back and you're like, this code is hard to read. 00:31:34.380 --> 00:31:37.640 It's just full of curly braces, semicolons, parentheses everywhere. 00:31:37.640 --> 00:31:41.880 I always thought we used to, those were just, that is what builds programming languages. 00:31:41.880 --> 00:31:43.960 To have a programming language, you had to have that. 00:31:43.960 --> 00:31:49.440 And then once I experienced Python and I went back, it kind of, it broke my mental model of the world. 00:31:49.440 --> 00:31:51.240 I'm like, you don't actually have to have those things. 00:31:51.240 --> 00:31:52.120 So why are they there? 00:31:52.120 --> 00:31:54.200 Anyway, what do you think about this article? 00:31:54.200 --> 00:31:57.200 You must like it somewhat because you hunted it down and tweeted it, right? 00:31:57.200 --> 00:32:02.180 It's old news for me because I didn't even invent the white space thing for Python. 00:32:02.180 --> 00:32:08.560 That was sort of handed to me on a silver platter by one of my mentors in the early 80s. 00:32:08.560 --> 00:32:08.820 Yeah. 00:32:08.820 --> 00:32:09.260 Yeah. 00:32:09.260 --> 00:32:10.220 Back in the ABC days. 00:32:10.220 --> 00:32:12.740 And in those days, it was an innovation. 00:32:12.740 --> 00:32:16.300 There was like one other language that had this. 00:32:16.300 --> 00:32:26.800 And Knuth had once said that he thought it would be a good idea, but he had never actually implemented the language or even experienced the language that implemented it. 00:32:26.860 --> 00:32:28.920 He just thought that it would be a good idea. 00:32:28.920 --> 00:32:29.320 Right. 00:32:29.320 --> 00:32:29.680 Right. 00:32:29.680 --> 00:32:39.820 The only thing that was a stumbling block for me was when I first started looking at Python, the editor I was using, I think it was, I think it was an Emacs something at the time. 00:32:39.820 --> 00:32:50.380 I'm not sure what I was using, but with the C++ code I was using, I had it set up so that if I double clicked on the closing bracket, it would jump to the top of the block. 00:32:50.760 --> 00:32:52.600 And I really liked that feature. 00:32:52.600 --> 00:32:56.420 And for some reason, that's the reason why I didn't like the white space thing at first. 00:32:56.420 --> 00:32:57.340 Like, how do I get back? 00:32:57.340 --> 00:33:04.420 But then I just went, okay, I'm going to like beginner's mind, just open mind, just embrace it and learn it as a new thing. 00:33:04.700 --> 00:33:07.320 And I didn't, like a week later, I didn't even miss it. 00:33:07.320 --> 00:33:07.980 Yeah. 00:33:07.980 --> 00:33:17.400 And of course, the new editors, the newer editors like PyCharm and stuff, at the bottom, they have little breadcrumbs of, you know, here's the class, here's the function, here's the if, here's the while, whatever. 00:33:17.400 --> 00:33:23.180 And you can jump between them, just like you were talking about, but like the entire hierarchy of, I don't know, the tokens or whatever. 00:33:23.320 --> 00:33:27.720 Yeah, and I just, I tend to write smaller functions now, so it's not as much of a deal. 00:33:27.720 --> 00:33:30.440 This is probably a good thing that it was hard. 00:33:30.440 --> 00:33:37.400 I was thinking, truly, that if you needed the attitude to help you find the top of the block, it must be pretty far away. 00:33:37.400 --> 00:33:37.760 Yeah. 00:33:37.760 --> 00:33:40.080 It's 4,000 lines. 00:33:40.080 --> 00:33:41.220 I hate scrolling so much. 00:33:41.220 --> 00:33:42.300 These functions are hard. 00:33:42.300 --> 00:33:43.260 Ah, yeah. 00:33:43.260 --> 00:33:44.440 How interesting. 00:33:44.440 --> 00:33:44.820 All right. 00:33:44.820 --> 00:33:46.540 Guido, do you have one more you want to share with us? 00:33:46.540 --> 00:33:48.080 Well, yeah, you gave me some homework. 00:33:48.080 --> 00:33:52.840 I didn't really do it, but there's like, and of course, this has to do with parsing. 00:33:52.840 --> 00:33:55.680 And so this may be a fairly esoteric library. 00:33:55.680 --> 00:34:09.180 But if you're writing a program that sort of does some manipulation of your code, and maybe it converts four space indents to two space indents or three space indents or whatever. 00:34:09.180 --> 00:34:20.060 Or maybe you're writing something like Black, which is the sort of Python code reformatting tool, but you don't like the way Black handles certain things. 00:34:20.060 --> 00:34:26.920 Or maybe you're writing some other thing that does analysis of source code. 00:34:26.920 --> 00:34:28.340 Maybe you're writing a linter. 00:34:28.340 --> 00:34:35.780 There are a couple of tools that you can use, and it turns out that one of them is in the standard library. 00:34:35.780 --> 00:34:40.020 There's something called lib223, which is a little hard to pronounce. 00:34:40.020 --> 00:34:45.240 It has the digit two and then the word T-O and then the digit three in the name. 00:34:45.240 --> 00:34:45.980 That is tricky. 00:34:45.980 --> 00:34:56.180 That is something I wrote probably over 15 years ago, or at least the core of it, which is yet another LL1 parser. 00:34:56.180 --> 00:35:00.140 But this one's written in Python rather than in C, like the original one. 00:35:00.540 --> 00:35:11.380 And actually Black ended up using lib223, except I think Lukasz had one issue that he couldn't figure out how to do with Black. 00:35:11.380 --> 00:35:17.240 And so he ended up vendoring a copy of lib223 and then butchering it a little bit. 00:35:17.240 --> 00:35:19.380 Which is how these things happen. 00:35:19.380 --> 00:35:24.420 I mean, if you look at what pip vendors, that's pretty scary, but there are good reasons for that too. 00:35:24.420 --> 00:35:33.860 So, but if you're writing your own, you should probably not use lib223 and not just because it's going to go out of style once the peg parser arrives. 00:35:33.860 --> 00:35:36.060 There are much better tools. 00:35:36.060 --> 00:35:44.440 And the one that I discovered a few months ago is actually written by some folks at Facebook mostly. 00:35:44.660 --> 00:35:46.460 It's called libcst. 00:35:46.460 --> 00:35:49.840 And they have unique capitalization. 00:35:49.840 --> 00:35:56.500 It's a capital L lib and then lowercase ib and then cst is all uppercase. 00:35:56.500 --> 00:36:00.480 And so it's a library for manipulating concrete syntax trees. 00:36:00.940 --> 00:36:06.260 And like lib223, it actually shares some code with lib223. 00:36:06.260 --> 00:36:15.660 I think the underneath is a parsing library called Parso, which itself is a butchered version of lib223. 00:36:15.660 --> 00:36:17.060 At least that's how it started. 00:36:17.060 --> 00:36:26.500 These tools are things that can parse Python code, but they produce a syntax tree that is the opposite of an abstract syntax tree. 00:36:26.500 --> 00:36:28.580 It's a very concrete syntax tree. 00:36:28.580 --> 00:36:43.740 And that means that every space, every comment, every bit of indentation is preserved or at least can be recovered from the information in that syntax tree. 00:36:43.740 --> 00:36:52.820 And oppose that with the typical abstract syntax tree, which in the end doesn't even remember where the parentheses are. 00:36:52.820 --> 00:36:53.720 Right, right. 00:36:53.720 --> 00:36:54.600 It just takes us up. 00:36:54.600 --> 00:36:55.880 Well, here's some conditional statement. 00:36:55.880 --> 00:36:57.280 Here's the two things we're testing. 00:36:57.280 --> 00:36:57.620 Yeah. 00:36:57.620 --> 00:36:57.860 Right. 00:36:57.860 --> 00:37:07.000 So this sounds much more useful if you want to do like a code analysis type of thing to say this thing you're doing here, you should do it in this other way or transform it over. 00:37:07.000 --> 00:37:09.420 But kind of preserve things like comments and style. 00:37:09.420 --> 00:37:09.840 Yeah. 00:37:10.200 --> 00:37:33.320 So lib223 itself started out that way as well is you read your source code using this customized parser. 00:37:33.320 --> 00:37:35.840 It gives you a concrete syntax tree. 00:37:35.840 --> 00:37:40.280 Then in that syntax tree, you're actually going to make changes. 00:37:40.280 --> 00:37:47.320 You're going to systematically rename a parameter or move things around or insert. 00:37:47.320 --> 00:37:54.160 In the 223 world, of course, it's used to turn things like iter items into items and iter keys into keys. 00:37:54.320 --> 00:37:56.520 And you can make that kind of changes. 00:37:56.520 --> 00:38:10.740 And so libCST also supports that, but it sort of has a slightly better API because 15 years ago when I started lib223, I didn't realize what an important tool it was going to be. 00:38:10.740 --> 00:38:20.360 And some of the way the white space is attached to nodes is exactly backwards from the way that is the most convenient to think about it and work with it. 00:38:20.360 --> 00:38:20.640 All right. 00:38:20.640 --> 00:38:21.040 Cool. 00:38:21.040 --> 00:38:25.760 Well, this sounds like it'll be really helpful for people building tools like Black or looking at code analysis and stuff. 00:38:25.760 --> 00:38:26.380 Right. 00:38:26.380 --> 00:38:36.260 Łukasz had, I think it was the 2019 talk, PyCon talk, where he described how Black uses both concrete syntax trees and the abstract syntax tree. 00:38:36.920 --> 00:38:42.940 It's a pretty fascinating talk for a very low level depth into these concepts. 00:38:42.940 --> 00:38:53.860 It wasn't until I watched that talk that I realized that Black compares the before and after abstract syntax tree to make sure that your code is guaranteed to run the same. 00:38:53.860 --> 00:38:56.220 So you don't really have to test for that. 00:38:56.220 --> 00:38:57.600 He's already testing for it. 00:38:57.600 --> 00:38:59.360 So that's pretty interesting. 00:38:59.360 --> 00:39:00.180 Yeah, that's very cool. 00:39:00.180 --> 00:39:01.840 That is a very neat feature. 00:39:01.840 --> 00:39:06.660 And it's actually an important trick in general for people who are doing transformation. 00:39:06.660 --> 00:39:16.060 to have some abstract way of double checking that your transformation left things in a decent state. 00:39:16.060 --> 00:39:16.740 Yeah, it's cool. 00:39:16.740 --> 00:39:17.340 Yeah, very cool. 00:39:17.340 --> 00:39:17.880 All right. 00:39:17.880 --> 00:39:19.000 Well, thanks for libcst. 00:39:19.000 --> 00:39:20.000 Guido, that's a great one. 00:39:20.000 --> 00:39:21.580 Now, that's it for our main topic. 00:39:21.580 --> 00:39:24.780 So just really quick things at the end that I just want to throw out there for people. 00:39:25.160 --> 00:39:29.640 One, Adam, who goes by Codependent Coder on Twitter, sent a message over and said, 00:39:29.640 --> 00:39:43.440 Hey, Django no longer supports Python 2 at all, which is pretty awesome because 1.11 has left long-term support, leaving only 2.2.12 onward, which has only Python 3 support. 00:39:43.440 --> 00:39:46.420 So yay for modern Python making its way through. 00:39:46.420 --> 00:39:47.040 That's good. 00:39:47.380 --> 00:39:53.480 And then last time we talked about 90% of coding is Googling and that's okay, or it's not. 00:39:53.480 --> 00:39:56.240 And we didn't really feel like that was our experience, right? 00:39:56.240 --> 00:39:57.980 As people have been around for a while. 00:39:57.980 --> 00:40:06.060 But I got to tell you, this last week I've been doing nothing but Pandas, Altair visualization, Jupyter notebook, and graphics. 00:40:06.620 --> 00:40:11.480 Because I'm building a whole set of dashboards for the Talk Python courses and whatnot. 00:40:11.480 --> 00:40:14.480 And basically the dashboards that I should have built a while ago. 00:40:14.480 --> 00:40:15.980 I Googled a lot. 00:40:15.980 --> 00:40:17.100 A whole lot. 00:40:17.100 --> 00:40:18.640 But that's the thing. 00:40:18.640 --> 00:40:27.420 It was like a two or three day blip of like, wow, I'm Googling like 25, 30% of my time because I don't know anything about these things. 00:40:27.420 --> 00:40:29.520 And how do I get this thing to line up with that bar? 00:40:29.520 --> 00:40:33.820 But now I'm back to just kind of mostly not doing that anymore, even after a few days. 00:40:33.820 --> 00:40:38.800 So I think generally what we said is true, but I do think there's like these blips of like, wow, I'm diving into something new. 00:40:38.800 --> 00:40:40.500 It's like mad search scrambling. 00:40:40.500 --> 00:40:44.160 But then I'm back to sort of using like more memory coding. 00:40:44.160 --> 00:40:45.700 I don't know what you call not Google coding. 00:40:45.700 --> 00:40:48.200 You've got to understand what you're doing. 00:40:48.200 --> 00:40:59.320 And that means you can't just Google for examples and copy and paste them in because then you can combine the examples and you have no idea what you're doing. 00:40:59.320 --> 00:41:00.520 And of course it doesn't work. 00:41:00.520 --> 00:41:02.040 At best it's frustrating, right? 00:41:02.040 --> 00:41:04.420 You're like, this worked, that worked, but together they don't work. 00:41:04.420 --> 00:41:05.740 And you just don't even know why, right? 00:41:05.740 --> 00:41:05.960 Yeah. 00:41:05.960 --> 00:41:06.780 So for sure. 00:41:06.780 --> 00:41:08.160 But yeah. 00:41:08.160 --> 00:41:11.020 So anyway, it's a follow up on our conversation last week, right? 00:41:11.020 --> 00:41:12.180 What do you got to throw out there for everyone? 00:41:12.180 --> 00:41:15.480 I'm going to say this on this show just to make sure I do it. 00:41:15.480 --> 00:41:18.340 There's like three days left for me to record my talk. 00:41:18.340 --> 00:41:18.720 Yeah. 00:41:18.720 --> 00:41:21.520 This is like forcing yourself to commit to it. 00:41:21.520 --> 00:41:22.220 So you're going to do it. 00:41:22.220 --> 00:41:22.780 Okay. 00:41:22.940 --> 00:41:23.760 Yes, definitely. 00:41:23.760 --> 00:41:25.040 So PyCon talk. 00:41:25.040 --> 00:41:26.360 I really do want to get it online. 00:41:26.360 --> 00:41:27.860 It's important stuff. 00:41:27.860 --> 00:41:29.260 It's about parameterization. 00:41:29.260 --> 00:41:37.200 I talked a couple episodes ago about having trouble switching back and forth at home with all this working from home stuff between Mac and Windows. 00:41:37.420 --> 00:41:40.560 I finally figured out the whole using command and control. 00:41:40.560 --> 00:41:42.620 So thank you to everybody. 00:41:42.620 --> 00:41:44.540 But apparently there's this really simple thing. 00:41:44.540 --> 00:41:47.400 Apple lets you just swap them on a keyboard. 00:41:47.400 --> 00:41:48.520 So that's what I'm doing. 00:41:48.520 --> 00:41:49.620 And it works great. 00:41:50.160 --> 00:41:58.000 And then also I had promised that I was going to have my cards project be able to work and publish to PyPI or the test PyPI. 00:41:58.000 --> 00:42:01.880 It doesn't work with setup tools SCM because I'm using Flit. 00:42:01.880 --> 00:42:12.340 So if somebody's got a way to figure out how to just somehow change the version string or bump that every time you merge or something like that, that'd be great. 00:42:12.340 --> 00:42:19.020 But otherwise, right now, I don't think there's a way to automatically push to PyPI if you're using Flit. 00:42:19.620 --> 00:42:21.580 Yeah, because it says that one's already uploaded. 00:42:21.580 --> 00:42:24.380 Maybe there's a GitHub action that will just randomize that or something. 00:42:24.380 --> 00:42:27.140 Because the version is embedded in the source code. 00:42:27.140 --> 00:42:33.180 And the trick that people are using with setup tools is the version is based on the version in GitHub. 00:42:33.180 --> 00:42:35.460 And you can't do that with Flit. 00:42:35.460 --> 00:42:37.480 So at least I haven't figured it out. 00:42:37.480 --> 00:42:38.620 But that's okay. 00:42:38.620 --> 00:42:40.260 I'll probably do something else. 00:42:40.260 --> 00:42:41.300 That's my extras. 00:42:41.300 --> 00:42:42.620 Guido, anything else? 00:42:42.620 --> 00:42:48.360 Even though I said it's hard to imagine Python going online, it actually is going online. 00:42:49.000 --> 00:42:50.240 At least some of it is. 00:42:50.240 --> 00:42:58.080 The first talk by the conference chair, Emily Morehouse, has been posted and many more will follow. 00:42:58.080 --> 00:42:59.400 Yeah, her welcome was really nice. 00:42:59.400 --> 00:43:04.820 The other thing, and as you mentioned, Django no longer supports Python 2 at all. 00:43:04.820 --> 00:43:13.360 Well, that's just fine because the very last release of Python 2, 2.7.18, was released a few days ago. 00:43:13.500 --> 00:43:14.460 Yeah, that's great. 00:43:14.460 --> 00:43:18.720 That must be kind of a load off of your shoulders to finally have that in the rearview mirror. 00:43:18.720 --> 00:43:19.880 I'm very happy. 00:43:19.880 --> 00:43:26.520 And I'm sad, of course, that we can't have an absolutely wild and crazy party in Pittsburgh like we were planning. 00:43:26.520 --> 00:43:28.400 Yeah, a big celebration on Zoom. 00:43:28.400 --> 00:43:29.320 It's just not the same. 00:43:29.320 --> 00:43:31.780 Just have to have a bigger one next year. 00:43:31.780 --> 00:43:33.800 That's one I don't know how to pull off. 00:43:33.800 --> 00:43:34.180 Yeah. 00:43:34.180 --> 00:43:35.440 Well, that's really good. 00:43:36.160 --> 00:43:36.480 All right. 00:43:36.480 --> 00:43:38.200 You guys ready for a really quick joke? 00:43:38.200 --> 00:43:39.280 All right. 00:43:39.280 --> 00:43:43.080 So here's a quick joke sent to us by Derek Chambers. 00:43:43.080 --> 00:43:45.960 And he may have even made this up for us. 00:43:45.960 --> 00:43:51.380 And this goes back to the sub interpreters and the multiple gills and all that. 00:43:51.380 --> 00:43:56.720 So you guys know how you can borrow money concurrently with asyncioUs? 00:43:57.280 --> 00:43:58.500 It's a terrible joke. 00:43:58.500 --> 00:43:59.380 That's a bad joke. 00:43:59.380 --> 00:44:02.080 Oh, that is very groan worthy. 00:44:02.080 --> 00:44:02.860 Very groan worthy. 00:44:02.860 --> 00:44:03.240 Excellent. 00:44:03.240 --> 00:44:06.680 Most of our jokes actually are around here, but that's how it goes. 00:44:06.680 --> 00:44:06.860 Yeah. 00:44:06.860 --> 00:44:07.840 And keep them coming. 00:44:07.840 --> 00:44:09.520 Keep sending us your bad jokes. 00:44:09.520 --> 00:44:10.360 Yeah. 00:44:10.360 --> 00:44:11.320 That's right. 00:44:11.320 --> 00:44:11.780 That's right. 00:44:11.780 --> 00:44:13.100 Python dad jokes. 00:44:13.100 --> 00:44:15.620 That should be a whole separate category. 00:44:15.620 --> 00:44:17.060 They absolutely should. 00:44:17.060 --> 00:44:17.580 They should. 00:44:17.580 --> 00:44:20.620 Well, Guido, it was really an honor to have you on the show. 00:44:20.620 --> 00:44:22.700 Thanks for coming and sharing your perspective on all this. 00:44:22.700 --> 00:44:23.480 Glad to be back. 00:44:23.480 --> 00:44:23.700 Yeah. 00:44:23.700 --> 00:44:25.560 And Brian, thanks as always. 00:44:25.560 --> 00:44:26.220 Good to be here with you. 00:44:26.220 --> 00:44:26.820 Cheers. 00:44:27.140 --> 00:44:27.300 Yep. 00:44:27.300 --> 00:44:28.060 Bye, everyone. 00:44:28.060 --> 00:44:28.400 Bye. 00:44:28.400 --> 00:44:29.260 Thanks, both of you. 00:44:29.260 --> 00:44:31.360 Thank you for listening to Python Bytes. 00:44:31.360 --> 00:44:33.900 Follow the show on Twitter via at Python Bytes. 00:44:33.900 --> 00:44:36.760 That's Python Bytes as in B-Y-T-E-S. 00:44:36.760 --> 00:44:39.980 And get the full show notes at pythonbytes.fm. 00:44:39.980 --> 00:44:44.200 If you have a news item you want featured, just visit pythonbytes.fm and send it our way. 00:44:44.200 --> 00:44:46.900 We're always on the lookout for sharing something cool. 00:44:46.900 --> 00:44:50.020 On behalf of myself and Brian Okken, this is Michael Kennedy. 00:44:50.020 --> 00:44:53.440 Thank you for listening and sharing this podcast with your friends and colleagues.