WEBVTT 00:00:00.001 --> 00:00:04.460 Hello and welcome to Python Bytes, where we deliver Python news and headlines directly to 00:00:04.460 --> 00:00:12.780 your earbuds. This is episode 197, recorded August 26th, 2020. Brian, can you believe it's 00:00:12.780 --> 00:00:15.700 the end of August? Even if I can't say it, it still is true? 00:00:15.700 --> 00:00:18.680 No, I can't. I don't know where August went. I just don't. 00:00:18.680 --> 00:00:23.120 I thought this whole pandemic thing would make the summer seem long and slow. It seems like it 00:00:23.120 --> 00:00:23.700 just went faster. 00:00:23.700 --> 00:00:28.800 Yeah, I've got like a Lego kit that I was planning on doing like the first week of summer vacation, 00:00:28.800 --> 00:00:33.320 and it's still sitting here. So yeah, for sure. Yeah, there's a lot of things I want to get done 00:00:33.320 --> 00:00:38.420 before the sun goes away and rain starts for six months straight. That's a Pacific Northwest problem, 00:00:38.420 --> 00:00:42.660 but it's our problem. All right. Now this episode is brought to you by us as well. We'll tell you 00:00:42.660 --> 00:00:46.840 more about the things that we're doing that we think you will appreciate later. Right now, 00:00:46.840 --> 00:00:50.880 I want to talk about something that I think we might've covered before, but I don't know if we've 00:00:50.880 --> 00:00:55.140 ever satisfactorily covered it. Maybe this time we'll get a little closer and that's AsyncIO. 00:00:55.140 --> 00:00:56.580 Oh yeah, I think that's a new topic. 00:00:56.800 --> 00:01:05.080 It's a totally new topic. Covered only less than GUIs. No. So there's a new, how should I put it, 00:01:05.080 --> 00:01:14.260 a new compatibility-like layer library that allows you to work a little bit better with AsyncIO 00:01:14.260 --> 00:01:22.720 and some of the other Async libraries that are not directly immediately the same as or built right on top of AsyncIO. 00:01:23.120 --> 00:01:32.840 Curio from David Beasley and Trio from Nathaniel Smith. So there's an article that talks about this. I'm going to mention as part of this conversation. 00:01:32.840 --> 00:01:40.320 And then say, Hey, Python has three well-known concurrency libraries built around Async and await syntax. AsyncIO, Curio, and Trio. 00:01:40.320 --> 00:01:45.900 True. But where's Unsync, people? Unsync is the best of all four of those. I don't know where Unsync is. 00:01:46.040 --> 00:01:55.320 Anyway, Unsync is not part of this conversation, but Unsync plays a role a little bit like this thing I'm going to mention today is AnyIO. 00:01:56.460 --> 00:02:03.900 And it's a pretty clever name because the idea is that it provides structured concurrency primitives built on top of AsyncIO. 00:02:03.900 --> 00:02:04.320 Okay. 00:02:04.320 --> 00:02:10.700 Right? So one of the challenges with AsyncIO is you can kick off a bunch of tasks and then not wait for them. 00:02:10.700 --> 00:02:12.860 And your program can exit or you can do other things. 00:02:12.860 --> 00:02:17.900 And maybe you've seen runtime warnings like task such and such was never awaited. 00:02:17.900 --> 00:02:19.600 You're like, Hmm, I wonder what that means. 00:02:19.600 --> 00:02:24.460 Well, that probably means your program exited while it was halfway done or something like that. Right? 00:02:24.880 --> 00:02:28.440 Or your thing returned a value before it waited for it to finish. Right? 00:02:28.440 --> 00:02:36.940 And at the low level, something that's a little bit frustrating or annoying that you've got to deal with is that you've got to make sure that all the stuff you started on the Async event loop, 00:02:36.940 --> 00:02:43.220 that you wait for that event loop to finish before your program completely shuts down or completely carries on. 00:02:43.860 --> 00:02:46.620 And so that's basically the idea of this library. 00:02:46.620 --> 00:02:55.900 It's a compatibility layer across those three types, those three different well-known concurrency libraries that provides this structured concurrency. 00:02:55.900 --> 00:03:08.580 So you look at Wikipedia, they say structured concurrency is a programming paradigm aimed at improving the clarity, quality, and development time of a computer program by using a structured approach to concurrent programming. 00:03:08.780 --> 00:03:17.740 The core concept is encapsulations of threads of execution by way of control flow constructs that have a clear entry and exit points. 00:03:17.740 --> 00:03:27.780 In Python, this mostly manifests itself through this library as async with blocks or async context managers. 00:03:28.380 --> 00:03:30.000 So you're like, I'm going to do some async work. 00:03:30.000 --> 00:03:32.780 So let's create a width block, do all the work in there. 00:03:32.780 --> 00:03:41.660 And then by the way, when you leave the width block, it's going to have made sure all the tasks that were started and the tasks started by those tasks and so on all finished. 00:03:41.660 --> 00:03:42.500 Oh, that's nice. 00:03:42.500 --> 00:03:43.420 Yeah, that's pretty cool. 00:03:44.160 --> 00:03:55.380 So the way it works is you basically go anyio.createTaskGroup and then from the task group, you can spawn other subtasks and it will keep track of those. 00:03:55.380 --> 00:04:00.780 If there's an exception, I believe it will cancel the other undone ones, the unfinished ones and so on. 00:04:00.780 --> 00:04:08.980 So it's about saying we're just going to go through this thing and it's all going to run here and like it enters at the top and it exits at the bottom of the width block. 00:04:08.980 --> 00:04:09.340 Okay. 00:04:09.460 --> 00:04:10.100 That's pretty cool, right? 00:04:10.100 --> 00:04:10.320 Yeah. 00:04:10.320 --> 00:04:10.620 Yeah. 00:04:10.620 --> 00:04:12.440 So I think that that's pretty neat. 00:04:12.440 --> 00:04:13.620 Also has other primitives. 00:04:13.620 --> 00:04:15.000 So that's like a real simple example. 00:04:15.000 --> 00:04:20.080 Other example or other things it does include synchronization, primitives, locks. 00:04:20.080 --> 00:04:30.840 So if you create a reentrant lock in Python, often called a critical section and things like C++ and whatnot, it's never, ever going to help you. 00:04:30.840 --> 00:04:32.340 Well, maybe that's a little bit strong. 00:04:32.480 --> 00:04:39.500 It's likely not going to help you because those mechanisms come from the operating system process level. 00:04:39.500 --> 00:04:42.100 And what they do is they make sure two threads don't run at the same time. 00:04:42.100 --> 00:04:49.260 Well, with asyncio, it's all a bunch of stuff that's being broken apart on a single thread, right? 00:04:49.260 --> 00:04:56.140 It's all on the one, wherever the event loop.run is, run to complete or whatever, like wherever that's happening, that's the thread. 00:04:56.140 --> 00:04:57.620 So like the thread locks don't matter. 00:04:57.620 --> 00:04:58.920 It's all the same thread. 00:04:59.120 --> 00:05:00.420 Like you're not going to block anything. 00:05:00.420 --> 00:05:10.160 So having primitives that will kind of function like threads to protect data while stuff is happening, while it's in temporarily invalid states, that's pretty cool for asyncio. 00:05:10.160 --> 00:05:10.640 Okay. 00:05:10.640 --> 00:05:12.860 So you need it or you don't need it? 00:05:12.860 --> 00:05:13.660 You probably need it. 00:05:13.660 --> 00:05:19.640 I think people often don't really think too much about these invalid states that programs get into. 00:05:19.640 --> 00:05:21.540 And you think, well, asyncio, it's going to be fine. 00:05:21.540 --> 00:05:25.860 And a lot of times what you're doing with asyncio is kind of standalone. 00:05:26.240 --> 00:05:28.120 Like I'm going to kick off this thing. 00:05:28.120 --> 00:05:30.140 And when it comes back, I'm going to take the data and do something. 00:05:30.140 --> 00:05:36.680 But if you're modifying shared data structures, you could still end up in some kind of event loop, erase condition. 00:05:36.680 --> 00:05:43.640 It's not as bad as like true threading because you're not going to, it's, I don't believe it's like a plus equals, right? 00:05:43.640 --> 00:05:47.640 Of something that actually might be multiple steps at the lower level runtime. 00:05:47.640 --> 00:05:50.220 I don't think that it would get broken up to that fine grained. 00:05:50.220 --> 00:05:59.600 But if you say like debit this account, this amount of money, or await, debit this account, this amount of money, await, put that amount into the other one. 00:05:59.600 --> 00:06:05.720 And some other one is like reading in some kind of loop, like that level of higher order, like temporarily invalid state. 00:06:05.720 --> 00:06:09.840 That could be a problem for asyncio and you want some kind of lock. 00:06:09.840 --> 00:06:18.020 So this comes with that, it comes with streams, which are similar to queues, timeouts through things like move on after or fail after a certain amount of time and so on. 00:06:18.020 --> 00:06:19.260 So it's pretty cool little library. 00:06:19.260 --> 00:06:20.100 Yeah, that's nice. 00:06:20.100 --> 00:06:20.460 Nice. 00:06:20.460 --> 00:06:24.440 My vote still for unsync is the best of the four, even though it was unmentioned. 00:06:24.440 --> 00:06:27.960 Isn't unsync built on those also? 00:06:28.120 --> 00:06:35.440 It's a compatibility layer that takes asyncio, threading, and multiprocessing and turns them all into things that you can await. 00:06:35.440 --> 00:06:36.080 Oh, yeah. 00:06:36.080 --> 00:06:36.820 Yeah. 00:06:36.820 --> 00:06:42.720 So don't you think there should be like a standard, like a, they should get together like some consortium and have a standard about this? 00:06:42.720 --> 00:06:43.300 Yeah. 00:06:43.300 --> 00:06:48.760 Well, they probably should, but we're still in the early stages of figuring out what the right API is. 00:06:48.760 --> 00:06:50.240 That's right. 00:06:50.240 --> 00:06:51.040 That's why they haven't done it. 00:06:51.040 --> 00:06:57.380 There's something else that has, that could use some standards and that's in a lot of data science libraries. 00:06:58.040 --> 00:07:03.140 There's an announcement that there's a new consortium for Python data API standards. 00:07:03.140 --> 00:07:06.800 So there is one happening and it's happening actually quite fast. 00:07:06.800 --> 00:07:13.000 They're getting started right away and there's activities to the announcements right away. 00:07:13.000 --> 00:07:23.000 Then in September, I believe they're going to kick off some work on data frames or on, no, starting with arrays and then move on to data frames. 00:07:23.000 --> 00:07:25.440 And so, okay, I'm getting ahead of myself. 00:07:25.940 --> 00:07:37.920 There are little blurbs says, one of the unintended consequences of the advances in multiple frameworks for data science, machine learning, deep learning, and numerical computing is that there is fragmentation. 00:07:37.920 --> 00:07:43.320 And in using the tools and then there are differences in common function signatures. 00:07:43.680 --> 00:07:58.200 They have one example that shows what the, generally a mean function to get the average or mean, people are going to like flame me for calling average mean, but as a commoner, I kind of think of those the same thing. 00:07:58.200 --> 00:08:04.120 But anyway, they show eight different, frameworks then, and some of them are common with other ones. 00:08:04.120 --> 00:08:09.920 And so there's five different interfaces for over the eight frameworks for just the mean function for an array. 00:08:09.920 --> 00:08:10.140 Yeah. 00:08:10.140 --> 00:08:12.880 And what's crazy is like, they all are basically the same. 00:08:12.880 --> 00:08:18.340 They're so, so similar, but they're not the same, not code wise the same, but they might as well be. 00:08:18.340 --> 00:08:18.780 Yeah. 00:08:18.780 --> 00:08:26.920 And so one of the issues is there's people are using more than one framework for different parts of their, maybe different parts of their data flow. 00:08:27.620 --> 00:08:37.020 And sometimes you can kind of forget which one you're using and having a lot of these things common actually would just make life easier, I think. 00:08:37.020 --> 00:08:49.420 So I think, I don't know how far they'll get with this, but I think it's a really, so they're not trying to make all of these, these frameworks look exactly the same, but with, commonalities in arrays and data frames. 00:08:49.900 --> 00:08:53.940 Or, and they note that arrays are also called tensors. 00:08:53.940 --> 00:09:01.720 So those are, trying to make some of those common is, I think a really good idea for some of the easy, simple stuff. 00:09:01.720 --> 00:09:02.560 why not? 00:09:02.560 --> 00:09:03.700 It seems like a great idea. 00:09:03.700 --> 00:09:05.180 It seems like a huge challenge though. 00:09:05.180 --> 00:09:12.500 Like who's going to give, whose function is going to be the one that's like, yeah, we're dropping this part of our API to make it look like everyone else's. 00:09:12.500 --> 00:09:12.900 Right. 00:09:12.900 --> 00:09:19.700 And that's why I think that they've, they've went through a lot of thought on how to go about with this process and try to convince people. 00:09:19.820 --> 00:09:43.380 So they're working with, they're trying to kind of be in between the framework authors and maintainers and the community and try to do some, some review process for different APIs, put a proposal out, have feedback from both from, from the different projects and from the community to have, have more of a, you know, more input to try to make it. 00:09:43.380 --> 00:09:47.480 It isn't just like one set of people saying, Hey, I think this should be this way. 00:09:47.480 --> 00:09:48.940 Yeah, no, it's, it's a good idea. 00:09:49.060 --> 00:09:53.460 It would be great if a lot of these applications or these frameworks may be renamed. 00:09:53.460 --> 00:10:01.180 If it's the same function, if it's like, for instance, mean in this example, if it's spelled exactly the same, maybe it should be the same API. 00:10:01.180 --> 00:10:08.480 And if you want a special version of it, maybe have a, have a underscore with an extra, you know, some reason why it's different. 00:10:08.480 --> 00:10:10.640 you can have extra different functions. 00:10:10.640 --> 00:10:11.060 Yeah. 00:10:11.060 --> 00:10:13.820 It seems like you could find some pretty good common ground here. 00:10:13.920 --> 00:10:14.520 It's a good idea. 00:10:14.520 --> 00:10:21.440 And if they make it happen, you know, it'd just be easier to mix and match frameworks and use the best or different situations. 00:10:21.440 --> 00:10:24.720 Cause I can certainly see you're like, Oh, I'm working with pandas here. 00:10:24.720 --> 00:10:31.460 It would be great if I could do this on CUDA cores with QPy, but I don't really know that it's close, but it's not the same. 00:10:31.460 --> 00:10:35.520 So I'm just going to keep stroking along here as opposed to change the import statement. 00:10:35.520 --> 00:10:36.260 Now it runs there. 00:10:36.260 --> 00:10:36.560 Yep. 00:10:36.820 --> 00:10:43.160 I don't know if it's ever really going to be like, you can just swap out a different framework, but for some of the common stuff, it'd really be great. 00:10:43.160 --> 00:10:50.060 And that's why one of the reasons why we're bringing it up is so that people can get on board and start being part of this review process if they care about it. 00:10:50.060 --> 00:10:50.260 Yeah. 00:10:50.260 --> 00:11:04.480 It also seems like there might be some room for like adaptive layers, like from QPy import pandas layer or something like that, where it basically, you talk to the, in terms of say a pandas API and it converts it to its internal. 00:11:04.660 --> 00:11:09.460 It's like, Oh, these, these arguments are switched in order or this keyword is named differently or whatever. 00:11:09.460 --> 00:11:11.080 And there's even things like differences. 00:11:11.080 --> 00:11:22.760 And even if the API looks the same or it's very similar, the default might be like in some cases, the default might be none versus false or versus no value or things. 00:11:22.760 --> 00:11:25.140 I don't know what no value means, but anyway. 00:11:25.140 --> 00:11:26.940 Yep. 00:11:26.940 --> 00:11:27.440 Cool. 00:11:27.440 --> 00:11:28.680 That's a good one. 00:11:28.680 --> 00:11:31.940 Now, also good is the things that we're working on. 00:11:31.940 --> 00:11:34.000 Brian, you want to tell folks about our Patreon? 00:11:34.220 --> 00:11:48.340 Actually, we've kind of silently announced it a while ago, but we've got 47 patrons now and it's set up for a monthly contribution and we, everything really appreciate people helping out because there are some expenses with the show. 00:11:48.340 --> 00:11:50.260 So that's a really cool. 00:11:50.260 --> 00:11:51.280 We'd love to see that grow. 00:11:51.720 --> 00:11:57.460 I don't, we'd also like to hear from people about how we'd like to come up with some special thank you benefits for patrons. 00:11:57.460 --> 00:12:00.760 And so I'd like to have ideas come from the community. 00:12:00.760 --> 00:12:04.120 If you can come up with some ideas, we will think about it. 00:12:04.120 --> 00:12:04.700 Yeah. 00:12:04.740 --> 00:12:06.520 So, and I'm trying to figure out how to get to it. 00:12:06.520 --> 00:12:08.440 So on our Python bytes. 00:12:08.440 --> 00:12:11.380 If you're on any episode page, it's there on the right. 00:12:11.380 --> 00:12:11.740 Okay. 00:12:11.740 --> 00:12:13.040 If you go to an episode page. 00:12:13.040 --> 00:12:13.560 Got it. 00:12:13.560 --> 00:12:13.760 Yep. 00:12:13.760 --> 00:12:19.460 Then it says on the right, I believe somewhere it says sponsors on, off the double check. 00:12:19.460 --> 00:12:20.140 I believe it does. 00:12:20.140 --> 00:12:20.540 Okay. 00:12:20.540 --> 00:12:21.440 We'll double check. 00:12:21.580 --> 00:12:23.060 It can for sure. 00:12:23.060 --> 00:12:24.400 If it doesn't already. 00:12:24.400 --> 00:12:29.260 And also, I want to just tell folks about a couple of things going on over at Talk Python 00:12:29.260 --> 00:12:30.000 training. 00:12:30.000 --> 00:12:35.160 We're doing a webcast on helping people move from using Excel for all their data analysis 00:12:35.160 --> 00:12:41.040 to pandas, basically moving from Excel to the Python data science stack, which has all sorts 00:12:41.040 --> 00:12:43.200 of cool benefits and really neat things you can do there. 00:12:43.200 --> 00:12:48.060 So Chris Moffitt is going to come on and writing a course with us and he's going to do a webcast, 00:12:48.060 --> 00:12:51.160 which I announced it like, well, yeah. 00:12:51.160 --> 00:12:54.580 It's 15 hours ago and already has like 600 people signed up for it. 00:12:54.580 --> 00:12:55.540 So it's free. 00:12:55.540 --> 00:12:56.620 People can just come sign up. 00:12:56.620 --> 00:12:59.500 It happens late September, September 29th. 00:12:59.500 --> 00:13:03.160 I'll put the link at the extra section of the show notes so people can find it there. 00:13:03.160 --> 00:13:07.080 And also the Python memory management course is out for early access. 00:13:07.080 --> 00:13:08.760 A bunch of people are signing up and enjoying it. 00:13:08.760 --> 00:13:13.740 So if you want to get to it soon, get to it early, people can check that out as well. 00:13:13.740 --> 00:13:14.500 Very exciting. 00:13:14.500 --> 00:13:17.260 So this next one I want to talk about has to do with manners. 00:13:17.260 --> 00:13:19.500 What kind of developer are you? 00:13:19.500 --> 00:13:20.720 Are you a polite developer? 00:13:21.040 --> 00:13:22.060 You're talking to the framework. 00:13:22.060 --> 00:13:26.780 Are you always checking in with it to see how it feels, what you're allowed to do? 00:13:26.780 --> 00:13:27.980 Are you kind of a rebel? 00:13:27.980 --> 00:13:29.360 You're just going to do what you like. 00:13:29.360 --> 00:13:33.620 But every now and then you get smacked down by the framework with an exception. 00:13:33.620 --> 00:13:38.900 I don't want to describe how a developer I am because I don't want the explicit tag on this episode. 00:13:40.360 --> 00:13:46.100 So there's an article that talks about something I think is pretty fun and interesting to consider. 00:13:46.100 --> 00:13:55.200 And it talks about the two types of error handling patterns or mechanisms that you might use when you're writing code. 00:13:55.840 --> 00:13:57.860 And Python naturally leans towards one. 00:13:57.860 --> 00:14:00.200 But there might be times you don't want to use it. 00:14:00.700 --> 00:14:05.860 And that is it's the two patterns are it's easier to ask for forgiveness than permission. 00:14:05.860 --> 00:14:07.360 That's one. 00:14:07.520 --> 00:14:10.520 And the other one is look before you leap or please may I. 00:14:10.520 --> 00:14:11.180 All right. 00:14:12.080 --> 00:14:18.840 And with the look before you leap, it's a lot of checks, like something you might do in C code. 00:14:18.840 --> 00:14:21.620 So you would say, I'm going to create a file. 00:14:21.620 --> 00:14:23.940 Oh, does the folder exist? 00:14:23.940 --> 00:14:27.100 If the folder doesn't exist, I'm going to need to create the folder. 00:14:27.100 --> 00:14:29.500 And then I can put the file there. 00:14:29.500 --> 00:14:30.780 Do I have permission to write the file? 00:14:30.780 --> 00:14:31.100 Yes. 00:14:31.100 --> 00:14:31.340 Okay. 00:14:31.340 --> 00:14:32.600 Then I'll go ahead and write the file. 00:14:32.600 --> 00:14:33.140 Right. 00:14:33.140 --> 00:14:37.040 You're always checking if I can do this, if this is in the right state and so on. 00:14:37.440 --> 00:14:39.380 That's the look before you leap style. 00:14:39.380 --> 00:14:45.940 The ask for forgiveness style is just try with open this thing. 00:14:45.940 --> 00:14:46.860 Oh, that didn't work. 00:14:46.860 --> 00:14:48.040 Catch exception. 00:14:48.040 --> 00:14:48.740 Right. 00:14:48.740 --> 00:14:51.260 Except some IO error or something like that. 00:14:51.260 --> 00:14:54.160 So there's reasons you might want to use both. 00:14:54.160 --> 00:14:58.760 Python leans or nudges you towards the ask for forgiveness. 00:14:58.760 --> 00:15:00.420 Try except version. 00:15:00.420 --> 00:15:04.380 The reason is, let's say you're opening a file and it's a JSON file. 00:15:04.380 --> 00:15:05.800 You might check first. 00:15:05.800 --> 00:15:07.280 Does the file exist? 00:15:07.520 --> 00:15:07.740 Yes. 00:15:07.740 --> 00:15:08.700 Do I have permission to read it? 00:15:08.700 --> 00:15:09.060 Yes. 00:15:09.060 --> 00:15:09.420 Okay. 00:15:09.420 --> 00:15:10.300 Open the file. 00:15:10.300 --> 00:15:11.420 Well, guess what? 00:15:11.420 --> 00:15:16.880 What if the file's malformed and you try to feed it over to like JSON load and you give 00:15:16.880 --> 00:15:17.540 it the file pointer? 00:15:17.540 --> 00:15:20.180 It's not going to say, sorry, it's malformed. 00:15:20.180 --> 00:15:21.320 It's going to raise an exception. 00:15:21.320 --> 00:15:25.600 It's not going to return it like a value, like malformed, constant, weird thing. 00:15:25.600 --> 00:15:29.500 It's just going to throw an exception and say, you know, invalid thing on line seven or 00:15:29.500 --> 00:15:29.720 whatever. 00:15:29.720 --> 00:15:30.000 Right. 00:15:30.000 --> 00:15:35.740 And so what that means is even if you wanted to do the look before you leap, you probably can't 00:15:35.740 --> 00:15:39.120 test everything and you're going to end up in a situation where you're still going to 00:15:39.120 --> 00:15:41.320 have to have the try except block anyway. 00:15:41.320 --> 00:15:44.360 So maybe you should just always do that. 00:15:44.360 --> 00:15:45.100 Right. 00:15:45.100 --> 00:15:47.680 Maybe you should just go, well, we're going to have to have exception handling anyway. 00:15:48.240 --> 00:15:52.700 That's just, we're going to do exception handling as much as possible and not do these tests. 00:15:52.700 --> 00:15:55.640 So that's the, this article over here. 00:15:55.640 --> 00:15:58.480 It's on the switwoski.com. 00:15:58.480 --> 00:16:00.540 Oh yeah. 00:16:00.540 --> 00:16:01.340 It's on Sebastian. 00:16:01.340 --> 00:16:02.780 Widooski. 00:16:02.780 --> 00:16:06.740 So yeah, it's his, I didn't realize that it was his article. 00:16:06.740 --> 00:16:08.900 So it's, his article. 00:16:09.060 --> 00:16:15.960 Anyway, he talks about like, what is the relative performance of these things and tries to talk 00:16:15.960 --> 00:16:18.120 about it from a, well, sure. 00:16:18.120 --> 00:16:22.400 It's cool to think of how it looks in code, but is one faster or one slower than the other? 00:16:22.400 --> 00:16:22.820 Okay. 00:16:22.820 --> 00:16:25.040 And this actually came up on talk Python as well. 00:16:25.040 --> 00:16:30.400 And so I said, look, if we're going to come up with an example, let's have a class and a 00:16:30.400 --> 00:16:31.000 base class. 00:16:31.340 --> 00:16:34.200 And let's have the base class define an attribute. 00:16:34.200 --> 00:16:36.680 And sometimes let's try to access the attribute. 00:16:36.680 --> 00:16:41.000 And when you don't have the base class, it'll, or when you only have the base class, it'll 00:16:41.000 --> 00:16:41.580 crash, right? 00:16:41.580 --> 00:16:42.640 Cause it's in the derived class. 00:16:42.640 --> 00:16:45.080 So let's say we have two ways to test. 00:16:45.080 --> 00:16:49.260 We could either ask, does it have the attribute and then try to access it? 00:16:49.260 --> 00:16:52.020 Or we could just right to access it. 00:16:52.020 --> 00:16:56.720 And it says, well, look, if it, if it works all the time and you're not actually getting 00:16:56.720 --> 00:17:00.820 errors and you're doing this, it's 30% slower to do the look before you leap. 00:17:00.820 --> 00:17:05.920 Cause you're doing an extra test and basically the try accept block is more or less free. 00:17:05.920 --> 00:17:11.900 Like it doesn't cost anything if there's not actually an error, but if you turn it around 00:17:11.900 --> 00:17:14.380 and you say, no, it's not there. 00:17:14.380 --> 00:17:20.300 All of a sudden it turns out the ask the try accept block is four times slower. 00:17:20.300 --> 00:17:21.700 That's a lot slower. 00:17:21.700 --> 00:17:22.340 Oh really? 00:17:22.340 --> 00:17:27.980 Because the raising of the exception, figuring out this call stack, all that kind of stuff 00:17:27.980 --> 00:17:28.540 is expensive. 00:17:28.540 --> 00:17:30.480 So instead of just going, does it have the attribute? 00:17:30.480 --> 00:17:34.360 You're going, well, let's do the whole call stack thing, every error, right? 00:17:34.360 --> 00:17:37.100 And create an object and throw it and all that kind of stuff. 00:17:37.100 --> 00:17:39.240 So it's a lot slower when there are errors. 00:17:39.240 --> 00:17:46.120 And anyway, it's a, an interesting thing to consider if you care about performance and things 00:17:46.120 --> 00:17:51.300 like parsing integers or parsing data that might sometimes fail, might not, you know, sometimes 00:17:51.300 --> 00:17:51.940 it doesn't fail. 00:17:51.940 --> 00:17:52.380 Yeah. 00:17:52.380 --> 00:17:52.780 Okay. 00:17:52.780 --> 00:17:54.120 Devil's advocate here. 00:17:54.120 --> 00:17:59.560 His example doesn't have any activity in the ask for forgiveness. 00:17:59.560 --> 00:18:01.080 If it isn't there. 00:18:01.080 --> 00:18:02.960 That's the way I saw when I first read it as well. 00:18:02.960 --> 00:18:04.100 There's two sections. 00:18:04.100 --> 00:18:08.460 There's like one part where he says, let's do it with the attribute on the drive class 00:18:08.460 --> 00:18:13.220 and let's do it again a second time by taking away the attribute and seeing what it's like. 00:18:13.220 --> 00:18:13.560 Right. 00:18:13.560 --> 00:18:17.340 But I mean, the code that if it, if it isn't exist, it just doesn't do anything. 00:18:17.340 --> 00:18:17.720 Right. 00:18:17.720 --> 00:18:20.280 Whereas in reality, you're still going to have to do something. 00:18:20.280 --> 00:18:20.500 Yeah. 00:18:20.500 --> 00:18:21.060 You got to do something. 00:18:21.060 --> 00:18:21.360 Notify the user. 00:18:21.360 --> 00:18:22.100 It's wrong. 00:18:22.100 --> 00:18:22.360 Yeah. 00:18:22.360 --> 00:18:22.700 Whatever. 00:18:22.700 --> 00:18:23.120 Yeah. 00:18:23.120 --> 00:18:23.280 Okay. 00:18:23.280 --> 00:18:23.520 Yeah. 00:18:23.520 --> 00:18:23.840 For sure. 00:18:23.840 --> 00:18:24.380 That's a good point. 00:18:24.380 --> 00:18:26.320 Like it's just basically a try except pass. 00:18:26.320 --> 00:18:26.840 Yeah. 00:18:27.240 --> 00:18:28.260 So what do you think about this? 00:18:28.260 --> 00:18:35.400 So what I think is you're going to have to write the try except anyway, almost all the 00:18:35.400 --> 00:18:35.700 time. 00:18:35.700 --> 00:18:38.520 And you don't want both. 00:18:38.520 --> 00:18:39.980 Like that doesn't seem good. 00:18:39.980 --> 00:18:42.340 That seems like just extra complexity. 00:18:42.340 --> 00:18:46.540 So when it makes sense, just go with ask for forgiveness. 00:18:46.540 --> 00:18:47.820 Just embrace exceptions. 00:18:47.820 --> 00:18:48.640 Right. 00:18:48.640 --> 00:18:52.320 Remember you have a finally block that often can like get rid of a test as well. 00:18:52.760 --> 00:18:57.660 You have multiple types of error except clauses are based on error type. 00:18:57.660 --> 00:19:00.100 I think people should do a lot with that. 00:19:00.100 --> 00:19:04.580 That said, if your goal is to like parse specific data, right? 00:19:04.580 --> 00:19:09.800 Like I'm going to read this number I got off by off of the internet by web scraping and there's 00:19:09.800 --> 00:19:10.700 a million records here. 00:19:10.700 --> 00:19:11.460 I'm going to parse it. 00:19:11.460 --> 00:19:15.280 If you want to do that a lot, a lot faster, that might make a lot of sense. 00:19:15.280 --> 00:19:20.900 I actually have a gist example that I put up trying to compare the speed of these things 00:19:20.900 --> 00:19:22.240 in a mixed case. 00:19:22.240 --> 00:19:26.680 So like the cases we're looking at here are kind of strange because it's like, well, 00:19:26.680 --> 00:19:29.300 there's, it's all errors or it's zero errors. 00:19:29.300 --> 00:19:29.620 Right. 00:19:29.620 --> 00:19:31.920 And then it doesn't really do anything, which are both weird. 00:19:31.920 --> 00:19:35.460 So I have this one where it comes up with like a million records strings. 00:19:35.460 --> 00:19:40.900 And most of the time they're number, they're legitimate numbers, like 4.2 as a string. 00:19:40.900 --> 00:19:41.760 And then you can parse it. 00:19:42.220 --> 00:19:48.400 And what I found was if you have more than 4% errors, I think it was four, like 4.5% or 00:19:48.400 --> 00:19:53.700 something errors, Aaron's data, it's slower to use exceptions. 00:19:53.700 --> 00:19:54.160 Okay. 00:19:54.160 --> 00:19:55.380 The cutoff is 4% errors. 00:19:55.440 --> 00:19:58.800 And I think if you have more than 4% errors, then the exceptions become more expensive. 00:19:58.800 --> 00:19:59.260 That's right. 00:19:59.260 --> 00:20:02.940 Anyway, it's something that people can run and get real numbers out of and play with it in 00:20:02.940 --> 00:20:04.640 a slightly more concrete way. 00:20:04.640 --> 00:20:05.720 But I don't know. 00:20:05.720 --> 00:20:06.460 What do you think? 00:20:06.500 --> 00:20:12.020 I think you start out by focusing on the code and making it easy and clear to understand 00:20:12.020 --> 00:20:13.100 and then worry about this stuff. 00:20:13.100 --> 00:20:13.600 Yeah. 00:20:13.600 --> 00:20:15.340 So I don't actually put either. 00:20:15.340 --> 00:20:18.660 I don't usually do the asking or the checking stuff. 00:20:18.660 --> 00:20:23.500 And that is one of the things that's good about bringing this up is that is more common in 00:20:23.500 --> 00:20:28.660 Python code is to not check stuff, just to, you know, to just go ahead and do it. 00:20:28.660 --> 00:20:30.620 And then I write a lot of tests. 00:20:30.620 --> 00:20:32.600 So I write a lot of tests around things. 00:20:32.600 --> 00:20:33.020 Yeah. 00:20:33.160 --> 00:20:39.240 And so either case checking for things or like, for instance, if it is, if it is input, 00:20:39.240 --> 00:20:41.200 if I've got user input, I'm checking for things. 00:20:41.200 --> 00:20:41.400 Yeah. 00:20:41.400 --> 00:20:45.580 I'm going to do it checks ahead of time because I want, because the behavior of what happens 00:20:45.580 --> 00:20:50.060 when it isn't there or when there's a problem, it isn't really a problem. 00:20:50.060 --> 00:20:55.360 It needs to be designed into the system as to what behavior to do when something unexpected 00:20:55.360 --> 00:20:55.900 happens. 00:20:55.900 --> 00:21:00.520 But the, in normal code, like, well, what happens if there's not an attribute? 00:21:00.520 --> 00:21:03.140 Well, you shouldn't be in that situation, right? 00:21:03.140 --> 00:21:04.300 You shouldn't be in that situation. 00:21:04.300 --> 00:21:05.580 And I usually push it up higher. 00:21:05.580 --> 00:21:08.060 I don't have try accept blocks all over the place. 00:21:08.060 --> 00:21:16.260 I have them around APIs that might not be trustworthy or around external systems or something. 00:21:16.260 --> 00:21:19.960 I don't put try accept blocks around code that I'm calling on my own code. 00:21:19.960 --> 00:21:20.980 Things like that. 00:21:20.980 --> 00:21:21.460 Yeah. 00:21:21.460 --> 00:21:22.520 I'm with you on that. 00:21:22.520 --> 00:21:23.300 That makes a lot of sense. 00:21:23.800 --> 00:21:27.760 The one time that I'll do the test, the look before you leave style, is if I think I can 00:21:27.760 --> 00:21:28.640 fix it, right? 00:21:28.640 --> 00:21:30.100 Does this directory not exist? 00:21:30.100 --> 00:21:31.360 I'm going to write a file to it. 00:21:31.360 --> 00:21:32.600 Well, I'm just going to make the directory. 00:21:32.600 --> 00:21:35.380 Then I'm going to write to it, you know? 00:21:35.380 --> 00:21:37.760 Those kinds of tests can get you out of trouble. 00:21:37.760 --> 00:21:41.940 But if you're just going to say this didn't work, chances are, you know, you still need 00:21:41.940 --> 00:21:44.080 the error handling and exception format anyway. 00:21:44.080 --> 00:21:44.480 Yeah. 00:21:44.480 --> 00:21:45.740 And you're probably going to throw an exception. 00:21:45.740 --> 00:21:46.920 So, anyway. 00:21:46.920 --> 00:21:47.800 Cool. 00:21:47.800 --> 00:21:52.760 So, you probably should get your code right, test it, and then just stick it in GitHub. 00:21:52.760 --> 00:21:54.480 Get in your repository. 00:21:54.480 --> 00:21:56.000 Make sure it's all up to date, right? 00:21:56.000 --> 00:21:58.520 Oh, I was wondering how you were going to do that transition. 00:21:58.520 --> 00:21:59.140 So, yeah. 00:21:59.140 --> 00:21:59.640 That's good. 00:21:59.640 --> 00:22:05.420 I was following a discussion on Twitter, and I think, actually, I think Anthony Shaw may 00:22:05.420 --> 00:22:06.660 have started it, but I can't remember. 00:22:06.660 --> 00:22:11.860 But dealing with different, if you've got a lot of repositories, just sometimes you have 00:22:11.860 --> 00:22:16.440 a lot of maintenance to do or a little, you know, some common things you're doing for 00:22:16.440 --> 00:22:17.320 a whole bunch of repos. 00:22:17.920 --> 00:22:24.640 And there's lots of different reasons why that might be the case or related tools or 00:22:24.640 --> 00:22:25.940 maybe just your work. 00:22:25.940 --> 00:22:26.960 You've got a lot of repos. 00:22:26.960 --> 00:22:31.300 But there's a project that came up in this discussion that I hadn't really played with 00:22:31.300 --> 00:22:33.320 before, and it's a project called My Repos. 00:22:33.320 --> 00:22:38.780 And on the site, it says you've got a lot of version control repositories. 00:22:38.780 --> 00:22:43.280 Sometimes you want to update them all at once or push out all your local changes. 00:22:43.880 --> 00:22:48.480 You may use special command lines in some repos to implement specific workflows. 00:22:48.480 --> 00:22:54.180 Well, the My Repos project provides an MR command, which is a tool to manage all your version 00:22:54.180 --> 00:22:55.260 control repositories. 00:22:56.200 --> 00:22:59.120 And the way it works is it's on directory structures. 00:22:59.120 --> 00:23:05.600 So it's a, and I usually have all of my repos that I'm working with under a common, like, 00:23:05.600 --> 00:23:08.400 projects directory or something so that I know where to look. 00:23:08.800 --> 00:23:12.120 And so I'm already set up for something like this might work. 00:23:12.120 --> 00:23:17.360 And you go into, into one of your repos and you type, if you have this installed, you type 00:23:17.360 --> 00:23:18.280 MR register. 00:23:18.280 --> 00:23:24.600 And it registers this under, registers that repo for common commands. 00:23:24.780 --> 00:23:30.940 And then whether you're in a parent directory or one of the specific directories and type 00:23:30.940 --> 00:23:36.960 a command, like for instance, if you say MR status, it'll do status on all of the repos 00:23:36.960 --> 00:23:40.820 that you care about or update or diff or something like that. 00:23:40.820 --> 00:23:47.340 And then you can build up even more complex commands yourself to do more complicated things. 00:23:47.520 --> 00:23:51.040 But I would, I mean, I'm probably going to use it right away just for just checking the 00:23:51.040 --> 00:23:56.000 status or doing polls or updates or something like that on, on lots of repos. 00:23:56.000 --> 00:23:57.120 So this looks neat. 00:23:57.120 --> 00:23:57.700 Yeah, it looks neat. 00:23:57.700 --> 00:23:58.920 I like the idea a lot. 00:23:58.920 --> 00:24:01.960 So basically I'm the same as you. 00:24:01.960 --> 00:24:08.180 I've got a directory, maybe a couple of levels, but all of my GitHub repos go in there, right? 00:24:08.180 --> 00:24:10.360 I grouped them by like personal stuff or work stuff. 00:24:10.360 --> 00:24:13.600 But other than that, they're just all next to each other. 00:24:13.600 --> 00:24:17.140 And this would just let you say, go do a Git poll on all of them. 00:24:17.280 --> 00:24:17.680 That's great. 00:24:17.680 --> 00:24:17.960 Yeah. 00:24:17.960 --> 00:24:22.860 Or like, for instance, at work, I've got often like three or four different related repos 00:24:22.860 --> 00:24:27.020 that if I switch to another project that I'm working on, I need to go through and make sure 00:24:27.020 --> 00:24:31.740 I'm not sure what branch I'm using or if everything's up to date. 00:24:31.740 --> 00:24:37.640 So being able to just go through all, like even two or three, being able to go and update 00:24:37.640 --> 00:24:41.640 them all at once or just even check the status of all, it'll save time. 00:24:41.640 --> 00:24:47.140 And then for the show, at least somebody that interviewed for a testing code, at least, 00:24:47.140 --> 00:24:53.300 Adam Johnson wrote an article called maintaining multiple Python projects with my repos. 00:24:53.300 --> 00:24:55.780 And we'll link to his article in the show notes. 00:24:55.780 --> 00:24:56.080 Yeah. 00:24:56.080 --> 00:24:56.440 Perfect. 00:24:56.440 --> 00:24:59.380 I like this idea enough that I wrote something like that already. 00:24:59.380 --> 00:24:59.860 You did. 00:24:59.860 --> 00:25:05.660 Well, what I wrote is something that will, it'll go and actually synchronize my GitHub account 00:25:05.660 --> 00:25:09.380 with a folder structure on my computer. 00:25:09.760 --> 00:25:15.120 So I'll go and just say like repo sync or whatever I called it. 00:25:15.240 --> 00:25:21.580 And it'll use the GitHub API to go and figure out all the repos that I've cloned or created 00:25:21.580 --> 00:25:26.060 and the different organizations like talk Python organization versus my personal one. 00:25:26.060 --> 00:25:29.620 And then it'll create folders based on the organization or where I forked it from and then 00:25:29.620 --> 00:25:30.100 clone it. 00:25:30.100 --> 00:25:32.300 And if it's already there, it'll update it within. 00:25:32.300 --> 00:25:34.040 It'll like basically pull all this down. 00:25:34.280 --> 00:25:34.960 Oh, that's cool. 00:25:34.960 --> 00:25:35.900 I need that. 00:25:35.900 --> 00:25:37.200 It was a lot of work. 00:25:37.200 --> 00:25:39.920 This seems like it's pre-built and pretty close. 00:25:39.920 --> 00:25:41.120 So it looks pretty nice. 00:25:41.120 --> 00:25:44.640 The one thing it doesn't do is it doesn't look like it doesn't go to GitHub and say, oh, 00:25:44.640 --> 00:25:47.220 what other repos have you created that you maybe don't have here? 00:25:47.220 --> 00:25:48.600 Maybe you want that. 00:25:48.600 --> 00:25:49.040 Maybe you don't. 00:25:49.040 --> 00:25:53.700 If you've like forked Windows source code and it's like 50 gigs, you don't want this tool 00:25:53.700 --> 00:25:54.940 that I'm talking about. 00:25:54.940 --> 00:25:58.080 But if you have reasonable size things like I forked Linux. 00:25:58.080 --> 00:25:58.840 Okay, great. 00:25:58.840 --> 00:25:59.820 That's going to take a while. 00:25:59.820 --> 00:26:03.080 But normally it would be I think it would be pretty neat. 00:26:03.080 --> 00:26:03.380 Yeah. 00:26:03.380 --> 00:26:06.220 Another thing that's neat around managing these types of things is Docker. 00:26:06.220 --> 00:26:10.340 And did you know that Python has an official Docker image? 00:26:10.340 --> 00:26:11.040 I did not. 00:26:11.040 --> 00:26:11.580 I didn't either. 00:26:11.580 --> 00:26:17.140 Well, I recently heard that, but it's fairly new news to me that there is an official Docker 00:26:17.140 --> 00:26:18.280 Python image. 00:26:18.280 --> 00:26:24.900 So theoretically, if you want to work with some kind of Linux Docker machine that uses Python, 00:26:24.900 --> 00:26:29.560 you can go and Docker run or to create the Python one. 00:26:29.560 --> 00:26:29.980 Right. 00:26:29.980 --> 00:26:32.940 So it's not super surprising. 00:26:32.940 --> 00:26:34.760 It's just called Python. 00:26:34.760 --> 00:26:35.280 Right. 00:26:35.280 --> 00:26:37.360 But it's yeah, it's just called Python. 00:26:37.360 --> 00:26:37.780 That's it. 00:26:37.780 --> 00:26:38.360 I believe so. 00:26:38.360 --> 00:26:40.900 Pretty straightforward working with it. 00:26:40.900 --> 00:26:47.900 But I'm going to talk about like basically looking through that Docker, that official Docker 00:26:47.900 --> 00:26:48.480 image. 00:26:48.480 --> 00:26:53.540 So Itamar Turner Trouring, who was on Talk Python not long ago, talking about Phil. 00:26:53.720 --> 00:26:57.700 And we also talked about Phil and Python bytes, the data science focused memory tool. 00:26:57.700 --> 00:27:02.680 He wrote an article called a deep dive into the official Docker image for Python. 00:27:02.680 --> 00:27:09.320 So basically it's like, well, if there's an official Docker image for Python, what is it? 00:27:09.320 --> 00:27:10.100 How do you set it up? 00:27:10.100 --> 00:27:15.200 Because understanding how it's set up is basically how do you take a machine that has no Python 00:27:15.200 --> 00:27:18.180 whatsoever and configure it in a Python way? 00:27:18.380 --> 00:27:20.420 So this is using Debian. 00:27:20.420 --> 00:27:22.740 That's just what it's based on. 00:27:22.740 --> 00:27:28.780 And it's using the Buster version because apparently Debian names all their releases after characters 00:27:28.780 --> 00:27:29.600 from Toy Story. 00:27:29.600 --> 00:27:30.720 I didn't know that. 00:27:30.720 --> 00:27:31.340 But yep. 00:27:31.340 --> 00:27:31.860 Buster. 00:27:31.860 --> 00:27:34.160 Buster is the current one. 00:27:34.420 --> 00:27:36.560 So it's going to create a Docker image. 00:27:36.560 --> 00:27:37.840 You create the Docker file. 00:27:37.840 --> 00:27:42.300 You say this Docker image is based on some other foundational one. 00:27:42.300 --> 00:27:43.740 So Debian Buster. 00:27:43.740 --> 00:27:50.940 And then it sets up slash user slash local slash bin for the environmental path. 00:27:50.940 --> 00:27:52.440 Because that is the first thing in the path. 00:27:52.440 --> 00:27:54.460 Because that's where it's going to put Python. 00:27:54.920 --> 00:28:01.040 It sets the locale explicitly to the EMV language is to UTF-8. 00:28:01.040 --> 00:28:05.920 There's some debate about whether this is actually necessary because current Python also defaults 00:28:05.920 --> 00:28:06.560 UTF-8. 00:28:06.560 --> 00:28:08.060 But, you know, here it is. 00:28:08.060 --> 00:28:13.760 And then it also sets an environment variable Python underscore version to whatever the Python 00:28:13.760 --> 00:28:14.380 version is. 00:28:14.380 --> 00:28:15.620 Right now it's 385. 00:28:15.620 --> 00:28:17.480 But whatever it is, that's kind of cool. 00:28:17.480 --> 00:28:22.040 So you can ask, hey, what version is in this system without actually touching Python? 00:28:22.500 --> 00:28:23.140 That's cool. 00:28:23.140 --> 00:28:27.840 And then it has to do a few things like register the CA certificates. 00:28:27.840 --> 00:28:32.480 Like, I've had people sending me messages that are taking courses. 00:28:32.480 --> 00:28:36.660 And they're trying to run the code from, you know, something that talks to requests, 00:28:36.660 --> 00:28:41.640 whether it's SSL certificate endpoint, HTTPS endpoint. 00:28:41.640 --> 00:28:45.760 And they'll say, this thing says the certificate is invalid. 00:28:45.760 --> 00:28:47.400 I'm like, the certificate's not invalid. 00:28:47.400 --> 00:28:48.160 What's going on here? 00:28:48.160 --> 00:28:48.680 Right? 00:28:48.680 --> 00:28:53.320 And almost always, something about the way that Python got set up on their machine didn't 00:28:53.320 --> 00:28:55.560 run the create certificate command. 00:28:55.560 --> 00:29:01.120 So there's like this step where Python will go download all the major certificate authorities 00:29:01.120 --> 00:29:02.640 and like trust them in the system. 00:29:02.640 --> 00:29:03.600 So that happens next. 00:29:03.600 --> 00:29:07.980 And then it actually will set up things like GCC and whatnot. 00:29:07.980 --> 00:29:09.780 So it can compile it. 00:29:09.780 --> 00:29:10.960 It's interesting. 00:29:10.960 --> 00:29:13.620 Downloads the source code, compiles it. 00:29:13.700 --> 00:29:17.300 But then what's interesting is it uninstalls the compiler tools. 00:29:17.300 --> 00:29:21.160 It's like, okay, we're going to download Python and we're going to compile it. 00:29:21.160 --> 00:29:23.700 But you didn't explicitly ask for GCC. 00:29:23.700 --> 00:29:24.760 We just needed it. 00:29:24.760 --> 00:29:25.600 So those are gone. 00:29:25.600 --> 00:29:26.160 Right? 00:29:26.160 --> 00:29:29.000 Cleans up the PYC files and all those kinds of things. 00:29:29.000 --> 00:29:33.840 And then it gives an alias to say that Python 3 is the same as Python. 00:29:34.040 --> 00:29:36.400 Like the command, you could do it without the 3. 00:29:36.400 --> 00:29:41.500 Another thing that we've gone on about that's annoying is like, I created a virtual environment. 00:29:41.500 --> 00:29:43.180 Oh, it has the wrong version of pip. 00:29:43.180 --> 00:29:44.280 Is my pip out of date? 00:29:44.280 --> 00:29:45.640 Your pip's probably out of date. 00:29:45.640 --> 00:29:46.880 Everyone's pip is out of date. 00:29:46.880 --> 00:29:52.540 Unless you're like a rare, like two-week window where Python has been released at the same time 00:29:52.540 --> 00:29:54.420 like the modern pip has been released. 00:29:54.420 --> 00:29:56.040 So guess what? 00:29:56.140 --> 00:29:59.120 They upgrade pip to the new version, which is cool. 00:29:59.120 --> 00:30:04.120 And then finally it sets the entry point of the Docker container, 00:30:04.120 --> 00:30:08.740 which is the default command to do if you just say Docker run this image, 00:30:08.740 --> 00:30:12.560 like Docker run Python 3.8-slim-buster. 00:30:12.560 --> 00:30:16.420 If you just say that by itself, what program is going to run? 00:30:16.420 --> 00:30:19.860 Because the way it works is it basically starts Linux and then runs one program. 00:30:19.860 --> 00:30:22.460 And that program exits, the Docker container goes away. 00:30:22.460 --> 00:30:25.400 And so it sets that to be the Python 3 command. 00:30:25.400 --> 00:30:32.780 So basically, if you Docker run the Python Docker image, you're going to get just the REPL. 00:30:32.780 --> 00:30:33.680 Interesting. 00:30:33.680 --> 00:30:37.340 Yeah, you can always run it with different endpoints like Bash and then go in and like do stuff to it 00:30:37.340 --> 00:30:40.320 or run it with MicroWSGI or Nginx or whatever. 00:30:40.320 --> 00:30:44.040 But if you don't, you're just going to get Python 3 REPL. 00:30:44.040 --> 00:30:52.300 Anyway, that's the way the official Python Docker image configures itself from a bare Debian buster 00:30:52.300 --> 00:30:53.900 over to Python 3. 00:30:53.900 --> 00:30:54.260 Neat. 00:30:54.260 --> 00:30:54.720 Yeah, neat. 00:30:54.720 --> 00:30:57.320 I thought it might be worth just thinking about like, what are all the steps? 00:30:57.320 --> 00:31:00.000 And you know, how does that happen on your computer? 00:31:00.000 --> 00:31:01.860 No, that's good. 00:31:01.860 --> 00:31:04.720 Because yeah, I have been curious about that. 00:31:04.720 --> 00:31:07.300 I was going to throw Python on a Docker image. 00:31:07.300 --> 00:31:08.740 What does that get me? 00:31:08.740 --> 00:31:09.660 Yeah, exactly. 00:31:09.660 --> 00:31:10.100 And that's what it is. 00:31:10.100 --> 00:31:14.980 Oh, you could also apt install Python 3 dash dev. 00:31:18.100 --> 00:31:19.060 Yeah, that might be cheating. 00:31:19.060 --> 00:31:19.400 All right. 00:31:19.400 --> 00:31:20.420 What's this final one? 00:31:20.420 --> 00:31:27.100 Oh, so it was recommended by, we covered some craziness that Anthony did an episode or two 00:31:27.100 --> 00:31:27.400 ago. 00:31:27.400 --> 00:31:32.060 And somebody commented that maybe we need to only in a pandemic section. 00:31:32.820 --> 00:31:33.820 Yeah, that sounds fun. 00:31:33.820 --> 00:31:36.280 So I selected Nanner Most. 00:31:36.280 --> 00:31:37.980 No, sorry. 00:31:37.980 --> 00:31:38.760 Nanner Nest. 00:31:38.760 --> 00:31:42.180 It's an optimal peanut butter and banana sandwich placement. 00:31:42.980 --> 00:31:46.740 So this is kind of an awesome article by Ethan Rosenthal. 00:31:46.740 --> 00:31:51.960 Talks about during the pandemic, he's been sort of having trouble doing anything. 00:31:52.760 --> 00:31:58.320 And so he really liked peanut butter and banana sandwiches when he was just still even. 00:31:58.320 --> 00:32:01.240 He got picked this habit up from his grandfather, I think. 00:32:01.240 --> 00:32:07.760 Anyway, this is using Python and computer vision and deep learning and machine learning and a 00:32:07.760 --> 00:32:13.260 whole bunch of cool libraries to come up with the best packing algorithm for a particular 00:32:13.260 --> 00:32:16.020 banana and the particular bread that you have. 00:32:16.020 --> 00:32:22.180 So you take a picture that includes both the bread and the bananas or the banana you have. 00:32:22.720 --> 00:32:28.480 And it will come up with the optimal slicing and placement of the banana for your banana 00:32:28.480 --> 00:32:28.880 sandwich. 00:32:28.880 --> 00:32:33.340 Wow, this is like a banana maximization optimization problem. 00:32:33.340 --> 00:32:36.380 So if you want, you got to see the pictures to get this. 00:32:36.380 --> 00:32:42.300 So like, if you're going to cut your banana into slices, and obviously the radius of the 00:32:42.300 --> 00:32:45.120 banana slice varies at where you cut it in the banana, right? 00:32:45.120 --> 00:32:45.920 Is it near the top? 00:32:45.920 --> 00:32:46.420 Is it in the middle? 00:32:46.420 --> 00:32:48.600 It's going to result in different size slices. 00:32:48.760 --> 00:32:56.100 On where do you place your bread, the banana circles on your bread to have maximum surface 00:32:56.100 --> 00:32:59.020 area of bananas relative to the what's left of the bread, right? 00:32:59.020 --> 00:32:59.720 Something like that? 00:32:59.720 --> 00:33:00.100 Yes. 00:33:00.100 --> 00:33:05.180 And he's trying to maximize, make it so that you have almost all of the bites of the sandwich 00:33:05.180 --> 00:33:08.260 have an equal ratio of banana, peanut butter, and bread. 00:33:08.380 --> 00:33:09.160 Oh yeah, okay. 00:33:09.160 --> 00:33:10.500 It's all about the flavor. 00:33:10.500 --> 00:33:16.720 I didn't understand like the real motivation, but yeah, you want to have an equal layer, right? 00:33:16.720 --> 00:33:18.860 So you don't want that spot where you just get bread. 00:33:19.080 --> 00:33:23.880 You actually learn quite a bit about all these different processes and there's quite a bit 00:33:23.880 --> 00:33:31.320 of math here talking about coming up with arcs for, you have to estimate the banana shape as 00:33:31.320 --> 00:33:40.260 part of an ellipse and using the radius of that to determine banana slices and estimates for, 00:33:40.260 --> 00:33:45.820 because you're looking at a banana sideways, you have to estimate what the shape of the banana 00:33:45.820 --> 00:33:49.460 circle will be and it's not really a circle, it's more of an ellipse also. 00:33:49.460 --> 00:33:51.240 Yeah, there's a lot going on here. 00:33:51.240 --> 00:33:56.300 Some advanced stuff to deliver your bananas perfectly. 00:33:56.300 --> 00:33:57.960 I love it. 00:33:57.960 --> 00:33:58.980 Actually, this is really interesting. 00:33:58.980 --> 00:33:59.480 This is cool. 00:33:59.480 --> 00:34:03.640 And it's, I mean, it's a silly application, but it's also a neat example. 00:34:03.640 --> 00:34:09.500 Yeah, actually, and this would be, I think, a cool thing for, to talk about difficult problems 00:34:09.500 --> 00:34:14.320 and packing for like a teaching, like in a school setting. 00:34:14.440 --> 00:34:18.580 I think this would be a great example to talk about some of these different complex problems. 00:34:18.580 --> 00:34:19.480 Yeah, totally. 00:34:19.480 --> 00:34:21.940 Well, that's it for our main items. 00:34:21.940 --> 00:34:26.960 For the extras, I just wanted to say I'll put the links for the Excel to Python webcast and 00:34:26.960 --> 00:34:30.180 the memory measurement course down there and we'll put the Patreon link as well. 00:34:30.180 --> 00:34:32.020 Let's see if you have anything else you want to share. 00:34:32.020 --> 00:34:32.720 No, that's good. 00:34:32.720 --> 00:34:33.120 Yeah, cool. 00:34:33.120 --> 00:34:34.720 How about sharing a joke? 00:34:34.720 --> 00:34:35.780 A joke would be great. 00:34:35.780 --> 00:34:41.660 So I'm going to describe the situation and you can be the interviewer slash boss who has the 00:34:41.660 --> 00:34:42.360 caption, okay? 00:34:42.360 --> 00:34:42.780 Okay. 00:34:42.780 --> 00:34:45.160 So the first, there's two scenarios. 00:34:45.160 --> 00:34:47.040 The title is Job Requirements. 00:34:47.040 --> 00:34:49.040 This comes to us from Eduardo Orochena. 00:34:49.040 --> 00:34:50.340 Thanks for that. 00:34:50.340 --> 00:34:56.740 And the first scenario is the job interview where you're getting hired. 00:34:56.900 --> 00:35:02.040 And then there's the reality, which is later, which is the actual on the job day to day. 00:35:02.040 --> 00:35:06.820 So on the job interview, I come in, I'm an applicant here and Brian, the boss says. 00:35:06.820 --> 00:35:09.260 Invert a binary tree on this whiteboard. 00:35:09.260 --> 00:35:15.000 Or some other random data structure, like quick sort this, but using some other weird thing, 00:35:15.000 --> 00:35:15.180 right? 00:35:15.180 --> 00:35:15.400 Yeah. 00:35:15.440 --> 00:35:20.760 Something that is kind of really computer science-y, way out there, probably not going 00:35:20.760 --> 00:35:22.940 to do, but kind of maybe makes sense, right? 00:35:22.940 --> 00:35:23.260 All right. 00:35:23.260 --> 00:35:25.920 Now I'm at the job and I've got like my computer. 00:35:25.920 --> 00:35:29.100 I have a huge purple buy button on my website that I'm working on. 00:35:29.100 --> 00:35:31.280 And the boss says, make the button bigger. 00:35:31.280 --> 00:35:33.000 Yep. 00:35:33.000 --> 00:35:33.900 That's the job. 00:35:33.900 --> 00:35:37.020 Yeah. 00:35:37.020 --> 00:35:38.580 Very nice. 00:35:38.580 --> 00:35:39.740 Good, good. 00:35:39.740 --> 00:35:40.020 All right. 00:35:40.020 --> 00:35:42.460 Well, I love the jokes and all the tech we're covering. 00:35:42.460 --> 00:35:42.960 Thanks, Brian. 00:35:42.960 --> 00:35:43.360 Yeah. 00:35:43.360 --> 00:35:43.760 Thank you. 00:35:43.760 --> 00:35:44.000 Yeah. 00:35:44.000 --> 00:35:44.200 Bye. 00:35:44.200 --> 00:35:46.180 Thank you for listening to Python Bytes. 00:35:46.180 --> 00:35:48.700 Follow the show on Twitter via at Python Bytes. 00:35:48.700 --> 00:35:51.540 That's Python Bytes as in B-Y-T-E-S. 00:35:51.540 --> 00:35:54.780 And get the full show notes at pythonbytes.fm. 00:35:54.780 --> 00:35:59.000 If you have a news item you want featured, just visit pythonbytes.fm and send it our way. 00:35:59.000 --> 00:36:01.700 We're always on the lookout for sharing something cool. 00:36:01.700 --> 00:36:04.800 On behalf of myself and Brian Okken, this is Michael Kennedy. 00:36:04.800 --> 00:36:08.240 Thank you for listening and sharing this podcast with your friends and colleagues.