WEBVTT 00:00:00.020 --> 00:00:04.280 Python has many string formatting styles, which have been added to the language over the years. 00:00:04.740 --> 00:00:13.160 Early Python used the percent operator to inject formatted values into strings, and we have string.format, which offers several powerful styles. 00:00:14.000 --> 00:00:21.000 Both were verbose and indirect, so fstrings were added in Python 3.6, but these fstrings lacked security features. 00:00:21.360 --> 00:00:22.240 Think about little bobby tables. 00:00:22.800 --> 00:00:26.380 And they manifested as fully formed strings to run timecode. 00:00:26.820 --> 00:00:31.740 Today, we talk about the next evolution of Python string formatting for advanced use cases. 00:00:32.380 --> 00:00:34.920 Think SQL, HTML, DSLs, and so on. 00:00:35.520 --> 00:00:35.860 t-strings. 00:00:37.060 --> 00:00:42.960 We have Paul Everitt, Dave Peck, and Jim Baker on the show to introduce the upcoming language feature. 00:00:43.600 --> 00:00:48.100 This is Talk Python To Me, episode 505, recorded May 13th, 2025. 00:00:49.400 --> 00:00:49.700 Are 00:00:49.700 --> 00:00:51.080 you ready for your host, please? 00:00:52.040 --> 00:00:54.800 You're listening to Michael Kennedy on Talk Python To Me. 00:00:55.480 --> 00:00:58.500 Live from Portland, Oregon, and this segment was made with Python. 00:01:24.960 --> 00:01:30.880 Subscribe to our YouTube channel over at talkpython.fm/youtube and get notified about upcoming shows. 00:01:31.480 --> 00:01:35.180 This episode is sponsored by Posit Connect from the makers of Shiny. 00:01:35.740 --> 00:01:39.540 Publish, share, and deploy all of your data projects that you're creating using Python. 00:01:40.140 --> 00:01:46.200 Streamlit, Dash, Shiny, Bokeh, FastAPI, Flask, Quarto, Reports, Dashboards, and APIs. 00:01:47.140 --> 00:01:48.760 Posit Connect supports all of them. 00:01:48.920 --> 00:01:54.360 Try Posit Connect for free by going to talkpython.fm/Posit, P-O-S-I-T. 00:01:55.160 --> 00:01:57.200 And it's brought to you by Auth0. 00:01:57.900 --> 00:02:02.160 Auth0 is an easy-to-implement, adaptable authentication and authorization platform. 00:02:02.960 --> 00:02:09.380 Think easy user logins, social sign-on, multi-factor authentication, and robust role-based access control. 00:02:09.759 --> 00:02:14.700 With over 30 SDKs and quick starts, Auth0 scales with your product at every stage. 00:02:15.300 --> 00:02:20.840 Get 25,000 monthly active users for free at talkpython.fm/auth0. 00:02:22.000 --> 00:02:26.160 Dave, Jim, and Paul, welcome to all three of you to Talk Python To Me. 00:02:26.720 --> 00:02:27.380 Paul, welcome back. 00:02:27.840 --> 00:02:29.520 Dave and Jim, welcome for the first time. 00:02:29.610 --> 00:02:30.220 Awesome to have you here. 00:02:30.420 --> 00:02:30.680 Thanks. 00:02:31.180 --> 00:02:31.380 Thanks. 00:02:31.740 --> 00:02:37.080 We are going to carry on an amazing tradition of Python string formatting. 00:02:38.120 --> 00:02:39.540 We've had the percent. 00:02:40.440 --> 00:02:41.360 We've had the plus. 00:02:41.960 --> 00:02:43.360 We've had the dot format. 00:02:44.000 --> 00:02:44.940 We've had the dot join. 00:02:45.540 --> 00:02:49.260 Everyone was very excited about fstrings back in 3.6 when they came out. 00:02:49.420 --> 00:02:58.020 And now, after quite a bit of work from the three of you and others, we're going to be talking about PEP 750 t-strings. 00:02:58.660 --> 00:02:58.800 Amazing. 00:02:59.160 --> 00:03:01.040 So congratulations on all of that. 00:03:01.460 --> 00:03:02.640 I think it's going to be a lot of fun. 00:03:02.960 --> 00:03:09.660 People may be surprised to think that, oh, there's an entire episode with three whole people on string formatting. 00:03:10.100 --> 00:03:10.280 Yes. 00:03:10.640 --> 00:03:11.120 Yes, that's right. 00:03:11.280 --> 00:03:12.180 There's actually a lot to it. 00:03:12.700 --> 00:03:15.840 This is a pretty rich API and a pretty big advancement. 00:03:16.220 --> 00:03:18.060 So we're going to dive into that. 00:03:18.280 --> 00:03:20.500 But before we do, how about a round of introductions? 00:03:21.280 --> 00:03:21.340 Dave? 00:03:21.860 --> 00:03:23.140 Hey, I'm Dave Peck. 00:03:23.300 --> 00:03:27.840 I'm a freelance software developer based in sunny Seattle, Washington. 00:03:28.640 --> 00:03:31.860 A freelance software developer is a polite way of saying I'm a computer weirdo. 00:03:32.240 --> 00:03:38.720 And I get to get into hopefully all kinds of good computer mischief, like working with Jim and Paul on new peps for Python. 00:03:39.080 --> 00:03:39.320 Awesome. 00:03:39.650 --> 00:03:40.320 Great to have you here. 00:03:40.480 --> 00:03:44.060 And always good to have another person from the Pacific Northwest. 00:03:44.800 --> 00:03:45.560 Jim, welcome. 00:03:45.920 --> 00:03:46.080 Hi. 00:03:46.540 --> 00:03:49.220 So, yeah, I'm a longtime Python user. 00:03:50.050 --> 00:04:00.300 I used to be very actively involved in the Jython project, which let me really learn the internals of both Jython and CPython, since we had to maintain a compatible implementation. 00:04:01.860 --> 00:04:06.480 So, you know, got deep into things like compilers and the standard library. 00:04:07.019 --> 00:04:13.100 And, yeah, it's great to talk about template strings or t-strings with you today. 00:04:14.040 --> 00:04:15.280 Paul, welcome back. 00:04:15.580 --> 00:04:17.200 How many episodes have you been on? Many. 00:04:17.620 --> 00:04:20.900 I don't know. Not enough, because Brett's ahead of me. 00:04:21.200 --> 00:04:21.799 I know. 00:04:22.420 --> 00:04:27.060 Brett Cannon, you're not allowed to be on Talk Python for five years until I catch up, and then you can come back. 00:04:28.060 --> 00:04:33.960 Well, you should also send your message to Anthony Shaw, who I think is currently on the leaderboard, number one. 00:04:34.240 --> 00:04:34.720 He's been on a lot. 00:04:34.780 --> 00:04:35.000 Yeah, 00:04:35.120 --> 00:04:39.420 and then you were talking with Chris McDonough, who was like episode three or something 00:04:39.420 --> 00:04:40.160 like that way 00:04:40.160 --> 00:04:40.860 back in the day. 00:04:41.620 --> 00:04:43.280 Briefly, I'm Paul. Hi, I'm Paul. 00:04:44.080 --> 00:04:47.960 I am now head of developer advocacy at JetBrains, the PieCharm people. 00:04:48.230 --> 00:04:51.400 I make coffee for Jim and Dave on this project. 00:04:52.620 --> 00:05:02.380 I let Jim do all the big thinking, and I let Dave go out and explain to complainers that we heard the same complaints for f-strings back in the day. 00:05:02.860 --> 00:05:04.660 So this has been a super fun 00:05:04.660 --> 00:05:05.500 project to be on. 00:05:05.500 --> 00:05:10.280 Yeah, it's very exciting, and I'm super interested to dive into it. 00:05:10.540 --> 00:05:12.300 Something I didn't really know a lot about. 00:05:12.840 --> 00:05:13.960 Let's dive into it, right? 00:05:14.060 --> 00:05:18.300 what are t-strings and why do they exist? 00:05:20.000 --> 00:05:21.000 Weren't f-strings good enough? 00:05:21.240 --> 00:05:23.420 I mean, they look kind of like f-strings when we use them. 00:05:23.800 --> 00:05:25.940 Yeah, that's a great part about them, right? 00:05:25.940 --> 00:05:27.100 They look like f-strings. 00:05:27.580 --> 00:05:39.260 They behave a lot like f-strings in terms of technical issues like the scoping of the interpolation expressions, but they're not f-strings in a very profound way. 00:05:40.100 --> 00:05:54.100 One of the things that we wanted to prevent was stuff like, you know, the classic XKCD comic about the Bobby Tables sequel injection, okay, where it becomes a drop tables inadvertently. 00:05:54.480 --> 00:05:55.520 And we can get, yeah, exactly. 00:05:56.000 --> 00:05:58.000 The traditional exploits of a mom. 00:05:58.540 --> 00:06:00.600 This is your son's skull calling. 00:06:00.980 --> 00:06:02.340 Did he break something well in a way? 00:06:02.660 --> 00:06:02.880 Yeah. 00:06:03.160 --> 00:06:11.020 And so this is, you know, the original language of the PEP actually referenced directly Bobby Tables in this comic. 00:06:11.080 --> 00:06:17.059 For whatever reason, we removed that, but we don't have to do that today in this conversation. 00:06:17.940 --> 00:06:19.820 It was a big driver for this work. 00:06:20.060 --> 00:06:23.480 And the reason is that f-strings are great. 00:06:23.820 --> 00:06:33.500 They're great for formatting, but they're also sort of a trap, I think, for people to use because it's you're formatting things, everything is working. 00:06:33.820 --> 00:06:45.780 and, oh, by the way, you just introduced the HTML injection or SQL injection, or you just happen to have something that doesn't format properly because you didn't consider a particular corner case. 00:06:46.180 --> 00:07:03.180 What we really wanted to do was move a lot of that out of the usual user experience and into a library that could go, some library, something for HTML, something for SQL, something for some other domain-specific language that would allow it to go and handle that appropriately. 00:07:03.780 --> 00:07:07.900 We'll get into more about what that means, I guess, throughout this conversation. 00:07:08.180 --> 00:07:09.720 But that's really where we started. 00:07:09.780 --> 00:07:14.020 We wanted the simplicity of using f-strings. 00:07:14.580 --> 00:07:18.200 We can get into more about what that means, but without some of the hazards. 00:07:18.720 --> 00:07:20.480 Excellent. Excellent introduction. 00:07:20.940 --> 00:07:23.300 And it's important that this is part of the language. 00:07:23.680 --> 00:07:26.880 It's officially accepted in Python 3.14. 00:07:27.500 --> 00:07:30.980 Oh, will the jokes overflow about Py, this version of Python, 00:07:31.860 --> 00:07:31.980 when 00:07:31.980 --> 00:07:32.400 it comes 00:07:32.400 --> 00:07:32.960 out in the fall? 00:07:33.060 --> 00:07:34.460 It's a memorative edition of Python. 00:07:35.040 --> 00:07:36.040 We're so glad to get into it. 00:07:36.540 --> 00:07:37.200 That's right. 00:07:37.320 --> 00:07:38.140 It's super cool. 00:07:39.080 --> 00:07:40.800 So it's going to be part of the language. 00:07:41.360 --> 00:07:51.740 And the reason I bring this up is it seems like it needs to be part of the language, not just an external library, to really take advantage of it and not be just some API. 00:07:51.890 --> 00:08:00.320 You construct strings in some weird string builder way, but through literally just, quote, start typing stuff, that has to be part of the language, right? 00:08:00.560 --> 00:08:01.740 Yeah, that's exactly right. 00:08:01.980 --> 00:08:04.700 I mean, as Jim mentioned, f-strings are wonderful. 00:08:04.940 --> 00:08:06.420 The syntax is powerful, it's robust. 00:08:06.930 --> 00:08:09.240 It became very popular because of that. 00:08:09.890 --> 00:08:16.680 But of course, there are these foot guns of using them for, you know, SQL and HTML where you might run into some injection problems. 00:08:17.880 --> 00:08:28.660 With t-strings, the key difference is that while f-strings evaluate to the standard string type, t-strings evaluate to a new type that's shipping in Python 3.14 later this year called template. 00:08:29.480 --> 00:08:37.380 And so while they look like the literal form looks like any other string, they're quite different in that respect. 00:08:37.560 --> 00:08:48.920 And the key thing about the template type is it lets you, as a programmer, decide what parts of the string were statically authored and what parts of the string were dynamically substituted or interpolated. 00:08:49.360 --> 00:08:53.100 And so just being able to do that as a language feature is a really big deal. 00:08:53.160 --> 00:08:55.380 It's not something you can do with fstrings directly. 00:08:55.940 --> 00:09:00.460 And once you know those things, you can start to say, okay, this is a SQL statement. 00:09:00.780 --> 00:09:07.520 Maybe I need to do something with the interpolation like escape its value before I construct the final string that I'm going to send over to my database. 00:09:07.980 --> 00:09:08.400 Yeah. 00:09:08.640 --> 00:09:13.560 If somebody were to work with an F string, it does the cool interpolation at runtime. 00:09:14.320 --> 00:09:22.900 However, the thing that your API or any sort of code gets access to is just the resulting string that comes out. 00:09:23.040 --> 00:09:27.960 And I think this is probably the biggest piece of understanding that people need to wrap their heads around. 00:09:28.440 --> 00:09:31.560 And we'll dive into some of the things people do need to wrap their heads around and how it's different. 00:09:31.920 --> 00:09:38.200 But instead of getting just here's the string result, which who knows why it says --drop table there. 00:09:38.580 --> 00:09:39.960 Maybe that's what they want. 00:09:40.540 --> 00:09:41.080 You don't know. 00:09:41.760 --> 00:09:41.880 Right? 00:09:42.020 --> 00:09:44.200 But here you would have here's part of the string. 00:09:44.660 --> 00:09:47.640 And then here's a place where a value goes with a name. 00:09:47.760 --> 00:09:52.780 And that thing, if you look it up by name, its value is --drop tables. 00:09:53.020 --> 00:09:55.520 well, maybe we'll escape that or whatever. 00:09:55.680 --> 00:09:56.240 You know what I mean? 00:09:56.980 --> 00:09:57.180 Right. 00:09:57.260 --> 00:10:01.620 You and Brian covered it twice in Python Bytes. 00:10:01.780 --> 00:10:08.180 And the first time, I'm going to exaggerate a little bit, but Brian was like, what is this? 00:10:08.880 --> 00:10:08.980 Why 00:10:08.980 --> 00:10:09.440 do we need it? 00:10:09.820 --> 00:10:10.660 We have enough, right? 00:10:11.280 --> 00:10:13.820 The second time, Brian was like, oh, I get it now. 00:10:14.520 --> 00:10:15.600 There's going to be a lot of that, Paul. 00:10:15.680 --> 00:10:16.480 And we certainly 00:10:16.480 --> 00:10:17.480 will have some explaining 00:10:17.480 --> 00:10:17.920 to you. 00:10:17.920 --> 00:10:18.720 Yeah, there's going to be a lot of this. 00:10:18.820 --> 00:10:20.200 As Dave said, being able 00:10:20.200 --> 00:10:20.840 to get at this. 00:10:21.140 --> 00:10:21.280 Sorry. 00:10:21.640 --> 00:10:21.780 What's that? 00:10:21.840 --> 00:10:23.100 Sorry, there's going to be a lot of that. 00:10:23.240 --> 00:10:24.740 There's going to be a lot of like, we already have f-strings. 00:10:24.980 --> 00:10:25.440 What is this? 00:10:25.980 --> 00:10:26.320 Yep, sure. 00:10:26.640 --> 00:10:28.080 An F string gives you a string. 00:10:28.500 --> 00:10:29.860 A template string gives you a template. 00:10:30.180 --> 00:10:31.700 And then later you will get a string. 00:10:32.160 --> 00:10:34.420 Later means going through a function. 00:10:34.900 --> 00:10:37.900 They can go and do cool things for you like escape values. 00:10:38.460 --> 00:10:41.020 Or you're doing an HTML templating system. 00:10:41.440 --> 00:10:48.040 Pass it a dictionary and it will generate a style attribute with some policies along the way. 00:10:48.160 --> 00:10:54.520 pass it a false or a Boolean and it will elide the entire thing or do all kinds of other things. 00:10:54.900 --> 00:11:05.220 Having the template structure that Dave described gives business value DSLs a chance to step in and operate on structure rather than strings. 00:11:05.440 --> 00:11:23.480 So when I write this code, I say value equals T, some interpolated string sort of thing. Is it interoperable with a string in the sense that if I have a function that expects a string, could I pass it? Much like path from pathlib kind of goes where string file names go, 00:11:23.900 --> 00:11:24.600 or does 00:11:24.600 --> 00:11:27.200 the thing working with it need to know, no, 00:11:27.200 --> 00:11:27.580 it needs 00:11:27.580 --> 00:11:34.400 to be transformed, like you say, like process this to a SQL statement or process this to an HTML fragment, and then you get a string. 00:11:34.640 --> 00:11:47.680 Yeah, and for templates, the answer is, very intentionally, they are not the same as strings. And so library authors are going to have to update their SQL libraries and their HTML libraries to expect this new template type. 00:11:49.019 --> 00:11:50.180 And that's very intentional. 00:11:50.860 --> 00:11:54.420 The other thing I would say is that templates don't have a direct route to strings. 00:11:54.580 --> 00:12:00.000 So if you call str of template, you just get the default repper back, right? 00:12:00.180 --> 00:12:05.020 Which is probably not something you want to be showing your users or it's not HTML that you're trying to render. 00:12:06.120 --> 00:12:06.320 And that, 00:12:06.520 --> 00:12:08.740 again, is very intentional. 00:12:08.940 --> 00:12:12.340 It's also unlikely to cause injection attacks and whatnot as well. 00:12:12.700 --> 00:12:13.180 you're getting that 00:12:13.180 --> 00:12:18.900 reference. So much, you know, all those parentheses and braces and whatnot, not likely to happen. 00:12:19.220 --> 00:12:40.760 Yeah, absolutely. And so library authors will have to update their libraries to add new methods that expect this template type. And presumably those methods won't also take a string. You know, if you're concerned about injection vulnerabilities, presumably you want to take this new dynamic template type that tracks what parts of the string are interpolated and what parts came from the developer themselves. 00:12:41.320 --> 00:13:01.620 Right. And treat them differently. Yeah. Yeah. Very interesting. So let's just talk about that a little bit. I see some use cases in the chat, but maybe we could list out some more. So for example, Nym4 says structured logging, preventing cross-site scripting, SQL injection. What are some of the motivations here? 00:13:01.780 --> 00:13:08.960 Yeah, those are all great use cases. Any type of injection vulnerability. So SQL and HTML were obviously at the top of our minds. 00:13:09.180 --> 00:13:19.840 But another one that, in fact, there's potentially a new PEP coming around for that's being discussed right now on the Python discussion boards has to do with command injection. 00:13:20.120 --> 00:13:25.260 So when you shell out, you're worried about the user-provided values there as well. 00:13:26.580 --> 00:13:27.120 Give me a sec. 00:13:27.220 --> 00:13:28.900 I'll try and remember what the actual PEP 00:13:28.900 --> 00:13:29.440 number is. 00:13:29.520 --> 00:13:30.920 There's os.system, 00:13:31.520 --> 00:13:31.780 and then 00:13:31.780 --> 00:13:34.760 you can give it a command like echo some string from the user. 00:13:35.200 --> 00:13:40.760 But it could, of course, be some string, quote, ampersand, ampersand, rm-rf, 00:13:41.360 --> 00:13:42.500 or something like that, right? 00:13:44.040 --> 00:14:01.780 And of course, as Paul mentioned, once you have the tools to help you prevent injection vulnerabilities in sort of a more general way in this general purpose fashion, you also have the ability to do all kinds of other fun and powerful things like what Paul mentioned with HTML, which is, hey, I don't just want to write, you know, a single attribute. 00:14:02.020 --> 00:14:06.760 I want to give you a dictionary and you write 20 attributes based on the contents of my Python dictionary. 00:14:08.140 --> 00:14:10.500 And there's no reason you can't do that now, which is exciting. 00:14:11.760 --> 00:14:11.960 Yeah, I 00:14:11.960 --> 00:14:12.600 would add to that 00:14:12.600 --> 00:14:26.940 if you wanted to, for example, do some interesting complex analytical SQL, where you're using common table expressions, or even you just want to go and have your analytical SQL. 00:14:27.200 --> 00:14:30.760 I want to be able to do it on this column name versus some other column name. 00:14:30.800 --> 00:14:33.860 We want to make it possible to do that in a safe fashion. 00:14:34.460 --> 00:14:42.940 These are things that are difficult to express with some of the typical wrappers that we might use with SQL, like SQLAlchemy. 00:14:43.680 --> 00:14:48.560 Maybe like, I don't think you can really do like CTEs and Django query sets and whatnot. 00:14:48.630 --> 00:14:53.100 But what I'm trying to say is that both of those tools do allow you to access raw SQL. 00:14:53.690 --> 00:14:57.240 But now you need to be able to compose that raw SQL in a way that's safe. 00:14:57.620 --> 00:15:06.760 and uses the information about where this interpolation is happening in order to properly put it in place. 00:15:06.880 --> 00:15:19.980 So if you are in a situation where maybe that CTE is something you can access, you can go and say, okay, I can insert it into the SQL or maybe a little more common usage here for a lot of people. 00:15:20.000 --> 00:15:22.040 I don't know how many people use common table expressions. 00:15:22.580 --> 00:15:22.960 I do. 00:15:22.960 --> 00:16:01.140 is to go and, you know, I just want to, again, select from this particular table name or this particular column name in a safe fashion. Or I want to go and use values that can't be properly expressed with placeholders. But maybe if I use like a, you know, a temporary table to insert it in. These are all techniques that we use when we do this sort of work. But now we have this opportunity to bring it into directly in the library and then make it possible for users to use it without really having to think, where did this come from? How do I go and make this such that it can be used in a where in clause, for example, that sort of thing. 00:16:02.460 --> 00:17:10.480 This portion of Talk Python To Me is brought to you by the folks at Posit. Posit has made a huge investment in the Python community lately. Known originally for our studio, they've been building out a suite of tools and services for Team Python. Today, I want to focus on hosting your Python-based data science workloads. This includes dashboards, reports, plots, interactive web apps, all the way to custom Flask and Django apps. Their service is Posit Connect. 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Let Posit Connect handle the delivery and DevOps involved in sharing your work. 00:17:26.839 --> 00:17:48.540 You focus on what you do best. So if you work on a data science team, you owe it to you and your org to check out Posit Connect. Visit talkpython.fm/connect today and get a three-month free trial to see if it's a good fit. That's talkpython.fm/connect. The link is in your podcast player show notes. Thank you, Deposit, for supporting Talk Python To Me. 00:17:50.440 --> 00:18:18.820 If I may, real quick, I got to give Jim a lot of credit on this as we've gone through the years on this. And Jim taught programming languages at University of Colorado Boulder. And so he knows all these patterns and all these languages and the implementations from his Jython years and stuff. And even now, he's still talking in chat about, hey, you know, Last year he was talking about how domain-specific languages could apply to Pandas and other data science stuff. 00:18:18.840 --> 00:18:26.960 And now he's talking about LLM interactions and chat and stuff like that, where you've got a little language, but it's got a little bit of structure. 00:18:27.580 --> 00:18:36.840 And what if you could, and then 500, you know, Discord messages later, Jim has invented something new and interesting. 00:18:38.120 --> 00:18:50.680 So it seems to me like there's also some interesting possibilities for like lazy evaluation for also some possibilities for like query optimization. 00:18:50.900 --> 00:19:01.160 You know, Jim was talking about databases, but there's a lot of different things, both from a performance perspective, but also potentially just from a tightly versus loosely coupled systems. 00:19:01.780 --> 00:19:08.260 Like maybe you could say something to the effect of like, and the username goes here, but that part of the system logging doesn't know what the username is. 00:19:08.660 --> 00:19:17.780 But somehow as the template gets rendered, the additional pieces could get filled in with real details, like the IP and the username is actually this, because over here we know. 00:19:17.840 --> 00:19:23.020 But when the logging happened, we got a template that just said, well, whatever you figure out, it goes here. 00:19:23.280 --> 00:19:24.720 How much of those things are possible now? 00:19:24.900 --> 00:19:37.960 Like, could you look at the structure bit of SQL and say, well, if we reorder this, or if we put something about, you know, some kind of SQL hint or something about indexes or other things in there, could you maybe get more from it? 00:19:38.140 --> 00:19:41.800 I was thinking someone might else answer this, but I will go for this. 00:19:42.040 --> 00:19:43.560 I mean, I think that's possible to do. 00:19:45.420 --> 00:19:56.500 In terms, you know, often we, you know, again, if we're thinking about SQL, we would, you know, dispatch this to, you know, some sort of, you know, the internal optimizer and, you know, whatever database you're working with. 00:19:56.800 --> 00:20:25.900 But, you know, again, the, you know, again, using the SQL example, you know, there's, there are multiple ways that you could potentially interface some, you know, more interesting, complicated ways of interacting with SQL that are kind of hard to, you know, either you can't express easily with placeholders, you know, the standard name placeholders or positional placeholders in SQL, or just, you know, basically you find people going composing SQL. 00:20:26.440 --> 00:20:28.480 and, you know, doing it in a bad way. 00:20:28.900 --> 00:20:42.120 But if you were to go and, you know, there's like a popular tool called SQL Glock, for example, that allows you to take SQL, re-express it as an abstract syntax tree, and then what can you do with that? 00:20:42.380 --> 00:20:49.420 Well, you know, the interesting thing about, you know, what we do with t-strings is it can be a front-end to such tools. 00:20:50.060 --> 00:21:39.680 So t-strings themselves are, you know, intentionally designed to have just this very limited, but at the same time, you know, let's say, you know, very powerful, you know, integration with Python, right? You have, you know, effectively an f-string specification of, you know, what's going to describe that template. You describe the interpolations, they can be nested and everything, but fundamentally at the end of the day, you get this template object out of it, which could be nested and whatnot, but it's still this simple, straightforward thing. And then you pass it to a function that can do interesting things with that. From a performance perspective, that's also something that we intentionally put together. I don't know, Dave, if you want to talk about that, what we did specifically for that, because I think that might be something you want to speak to. 00:21:39.940 --> 00:21:51.780 Yeah, absolutely. Well, if you take a look at what's inside the template type, there are basically two tuples that sit there. There's a tuple called strings and a tuple called values or interpolations. 00:21:51.950 --> 00:21:53.060 You can kind of work both ways. 00:21:54.500 --> 00:21:59.540 And so as you might expect, the strings are the static parts that are part of the literal string that you specify. 00:22:00.400 --> 00:22:03.620 And the values or interpolations are the dynamic parts. 00:22:04.600 --> 00:22:14.320 And we kind of made it so that no matter how you write your literal, it's always the case that there is at least one string in that strings tuple, even if it's the empty string. 00:22:14.760 --> 00:22:29.360 So T quote, quote, gives you a template with no interpolations, with an empty tuple for interpolations, and with just a single quote for strings. And we ensure that there's always one more string than there are values or interpolations. 00:22:29.940 --> 00:23:21.760 And the reason we do that is that allows you to basically, the string's tuple becomes a useful cache key in many cases for memorizing. So if you process a template once with your HTML function, you might sit back and say, okay, I've seen this structure of HTML before, and the next time I do it, all I need to do is fill in the gaps. And so that we think is just like a really basic optimization that you can use. And we're seeing that use, Paul, you might want to mention the TDOM library that I know you and others have been working on in the last little while. But it's just a basic optimization that we can offer. I think it is worth calling out, though, that, and I know we mentioned this earlier, but probably worth calling out once more just to make it explicit, that t-strings like f strings are eagerly evaluated, right? So if you have hello, 00:23:22.240 --> 00:23:23.240 curly 00:23:23.240 --> 00:23:28.320 braces name, and name isn't in scope, you will get a name error just like with an f string. 00:23:29.260 --> 00:23:49.760 And so you might say, well, that feels a little weird to me because don't I want to reuse these things multiple times? And this is one of those cases where the word template is just an overloaded term in the computing world. And so if you're coming from the Jinja world or the Django templates world, you're probably used to the idea that I have this structure and I'm going to keep substituting values into it. 00:23:50.580 --> 00:23:56.240 And that's a little bit different than the other use of the word template, which comes from, say, the JavaScript side of the world. 00:23:56.410 --> 00:23:58.700 So JavaScript has tag template literals. 00:23:58.840 --> 00:24:02.220 If you've written any JavaScript code, you've probably run across them before. 00:24:03.300 --> 00:24:06.520 And there, like with t-strings, they're eagerly evaluated. 00:24:07.200 --> 00:24:10.460 So, you know, of course, you have the full generality of Python available to you. 00:24:10.880 --> 00:24:20.600 So you can just write a function that takes the parameters that you want to substitute and returns a T string, call it multiple times with different values, and you'll get different template instances out the other side. 00:24:20.900 --> 00:24:27.280 Probably just worth calling that out so that it's clear to listeners that there is this kind of funny overloading the word template. 00:24:27.780 --> 00:24:29.900 But yeah, back to the point about optimization. 00:24:30.540 --> 00:24:45.160 We're pretty excited about just the basic opportunities for building optimized template processing code, like an HTML function or a SQL function that works on top of this basic structure that we provide in PEP 750. 00:24:45.280 --> 00:24:53.820 Yeah, and I think one thing you can think about is, again, we may be getting a little too into the weeds here, but let's get into the weeds. 00:24:55.120 --> 00:25:02.060 You can think about the template as basically providing this interesting way of describing your arguments. 00:25:03.460 --> 00:25:08.180 And then you pass it to some sort of function, HTML, SQL, you name it. 00:25:09.100 --> 00:25:13.140 And basically, it's going to evaluate with respect to those arguments. 00:25:13.740 --> 00:25:26.740 But, you know, if you, so we basically, you know, if I have an HTML function, I'm going to want to look it up with that dot strings, template dot strings. 00:25:27.420 --> 00:25:31.040 Say I parsed this and I know how to go and work with this fragment. 00:25:31.200 --> 00:25:40.240 I already know where all the pieces need to go, the holes that need to be filled in by these interpolations, and it could be done very quickly. 00:25:41.380 --> 00:25:46.300 And so we've put a lot of effort in terms of thinking about what is that optimization path. 00:25:46.540 --> 00:25:48.040 And there's also related aspects. 00:25:48.460 --> 00:25:55.700 Why is this another reason this is built into the language is because you can get lexical scope as opposed to dynamic scope. 00:25:56.120 --> 00:26:00.660 You think that lexical, you know, you might think that dynamic scope is always the thing that's going to work for you. 00:26:01.120 --> 00:26:04.440 But no, this is the thing that brought Paul and I together on this project. 00:26:04.920 --> 00:26:10.260 It's exactly, you know, you can't use dynamic scope when you would expect it. 00:26:10.600 --> 00:26:15.920 So, yeah, if we want to go to that scope issue when calling components from list comprehension. 00:26:16.850 --> 00:26:20.820 So, Paul, if you want to speak to this a little bit, those are the problems you experienced. 00:26:21.880 --> 00:26:30.360 Sure. And this is, oh, my gosh, Jim in the first round of this and Dave in the second round of this in the PEP and the comments. 00:26:31.160 --> 00:26:37.160 This this damn thing had more comments on it than every other PEP in the history of civilization. 00:26:37.440 --> 00:26:38.660 Almost it felt that way. 00:26:39.250 --> 00:26:45.380 Major changes between the first draft and the second draft from lazy evaluation, tag template functions, all those things. 00:26:46.360 --> 00:26:52.180 But one that comes up pretty frequently is I could just do this with this script frame. 00:26:52.680 --> 00:26:56.060 And you can, but you can't and you shouldn't either way. 00:26:56.800 --> 00:27:05.780 But there is a nuance about scoping that bit me right here on the screen in this ticket that was the origin story of Gemini talking to each other. 00:27:06.420 --> 00:27:39.080 2020, a predecessor that mimicked t-strings in sysget frame from the people behind the JavaScript package called HTM. They did a port to Python called HTMPy for doing powerful template languages kind of closer to the language, something that in the JavaScript world, this is a replacement for JSX. It doesn't need tooling. And so they wanted to bring that kind of experience, language-centric templating. They wanted to bring it to Python, but hit this issue about scope. 00:27:39.720 --> 00:27:59.520 Yeah. And it seems like it's just this obscure thing, but it isn't. You know, you use a nested function, it pops up. Use a generator expression, it pops up. Use a list comprehension, it pops up. So things that you might commonly want to use, now you need to know you shouldn't do that. So that's one thing. The second thing is it's slow. And it basically also breaks 00:27:59.520 --> 00:28:01.500 a lot of optimizations that have 00:28:01.500 --> 00:28:03.820 been introduced into Python in recent years. 00:28:04.400 --> 00:28:05.300 So you don't want to do that either. 00:28:06.360 --> 00:28:07.200 By using... 00:28:07.280 --> 00:28:07.600 And the 00:28:07.600 --> 00:28:09.980 creator of this hack, Barry said, don't use this hack. 00:28:10.580 --> 00:28:12.140 Well, I mean, there are 00:28:12.140 --> 00:28:16.500 good reasons to go and use sysgift frame, and especially there are historical good reasons. 00:28:17.140 --> 00:28:27.340 But I think we have, again, so it's something that comes up because, you know, if you have dug into the internals of Python, you've looked at the inspect, you know you can do certain things. 00:28:27.900 --> 00:28:32.080 And I think that's a fantastic way to explore new capabilities. 00:28:32.710 --> 00:28:35.520 But it is not necessarily what you want to go rely on because, 00:28:36.080 --> 00:28:36.700 again, 00:28:36.900 --> 00:28:42.380 the thing I would have taught in the class, what is the difference between dynamic and lexical scope? 00:28:42.880 --> 00:28:44.500 Well, here's where it really bites you. 00:28:46.320 --> 00:28:49.400 This portion of Talk Python To Me is brought to you by Auth0. 00:28:49.960 --> 00:28:51.080 Do you struggle with authentication? 00:28:52.080 --> 00:28:53.820 Sure, you can start with usernames and passwords. 00:28:54.160 --> 00:28:58.500 But what about single sign-on, social auth, integration with AI agents? 00:28:59.140 --> 00:29:01.320 It can quickly become a major time sink. 00:29:01.790 --> 00:29:04.440 And rarely is authentication your core business. 00:29:05.100 --> 00:29:09.680 It's just table stakes that you got to get right before you can move on to building your actual product. 00:29:10.280 --> 00:29:12.120 That's why you should consider Auth0. 00:29:12.620 --> 00:29:16.940 Auth0 is an easy to implement, adaptable authentication and authorization platform. 00:29:17.660 --> 00:29:24.060 Think easy user logins, social sign-on, multi-factor authentication, and robust role-based access control. 00:29:24.780 --> 00:29:31.180 With over 30 different SDKs and quick starts, Auth0 scales with your product at every stage. 00:29:31.860 --> 00:29:37.000 Auth0 lets you implement secure authentication and authorization for your preferred deployment environment. 00:29:37.370 --> 00:29:45.380 You can use all of your favorite tools and frameworks, whether it's Flask, Django, FastAPI, or something else, to manage user logins, roles, and permissions. 00:29:46.200 --> 00:29:51.040 Leave authentication to Auth0 so that you can start focusing on the features your users will love. 00:29:51.900 --> 00:29:56.340 Auth0's latest innovation, Auth4Gen AI, which is now available in developer preview. 00:29:56.880 --> 00:30:07.720 Secure your agentic apps and integrate with the Gen AI ecosystem using features like user authentication for AI agents, token vault, async authorization, and FGA for RAG. 00:30:08.480 --> 00:30:21.480 So if you're a Python developer or data scientist looking for an easy and powerful way to secure your applications, Get started now with up to 25,000 monthly active users for free at talkpython.fm/auth0. 00:30:22.120 --> 00:30:24.280 That's talkpython.fm/auth0. 00:30:24.400 --> 00:30:26.140 The link is in your podcast player's show notes. 00:30:26.820 --> 00:30:28.800 Thank you to Auth0 for supporting the show. 00:30:29.820 --> 00:30:34.240 Let's talk about HTML templates because I know, Paul, that was a lot of your interest in this, right? 00:30:34.920 --> 00:30:35.120 Indeed. 00:30:35.960 --> 00:30:38.160 Michael, you and I are like web originals, 00:30:38.280 --> 00:30:38.400 right? 00:30:39.540 --> 00:30:41.280 You're a big fan of Chameleon. 00:30:41.600 --> 00:30:46.720 Whenever you encounter a new web framework, the first thing you do is make a package for that that gives a 00:30:46.720 --> 00:30:47.320 chameleon support. 00:30:47.780 --> 00:30:48.020 That's right. 00:30:48.080 --> 00:30:53.640 You want FastAPI, just put the FastAPI chameleon decorator on there and you're back to have proper language. 00:30:55.100 --> 00:30:55.460 Yes. 00:30:56.680 --> 00:31:04.820 But my feeling has been that Python web development, particularly templating, is stuck in the early 2000s. 00:31:05.020 --> 00:31:06.240 I went and looked up recently. 00:31:06.740 --> 00:31:09.760 I think Jinja was first released in 2008. 00:31:10.100 --> 00:31:17.060 And there was a feeling back then that HTML and web design was something different than software. 00:31:17.560 --> 00:31:20.720 Separation of concerns, but more importantly, separation of people. 00:31:21.130 --> 00:31:23.840 You wanted to keep the templating people away from the software. 00:31:24.160 --> 00:31:27.820 You've got your designers and you've got your developers and they exchanged 00:31:27.820 --> 00:31:28.460 the CSS. 00:31:29.000 --> 00:31:32.060 I'm going to give you this sandbox where you can't break things. 00:31:32.170 --> 00:31:35.220 And it's going to be like Python, but not really Python. 00:31:36.100 --> 00:31:38.580 And the world doesn't work that way anymore. 00:31:38.940 --> 00:31:41.440 Front-end development is software. 00:31:41.890 --> 00:31:43.860 In the JavaScript world, it's software. 00:31:44.100 --> 00:31:44.760 It's components. 00:31:45.360 --> 00:31:45.980 It's tooling. 00:31:46.520 --> 00:31:47.880 It's testing. 00:31:48.440 --> 00:31:53.560 It's all of these things where people expect powerful tooling as part of software. 00:31:54.140 --> 00:31:54.840 We haven't. 00:31:54.970 --> 00:32:02.420 And there have been some things starting to get into this area, but this was what I was originally interested in, what Jim and I had talked about quite a bit. 00:32:02.640 --> 00:32:04.220 Dave comes from a similar background. 00:32:04.900 --> 00:32:11.760 And we want, in a general sense, we want DSLs, domain-specific languages, that are closer to Python. 00:32:12.200 --> 00:32:15.200 So when you say, here's a symbol, it's a symbol. 00:32:15.530 --> 00:32:17.880 And you know the scoping rules because it's just Python. 00:32:18.070 --> 00:32:20.220 It isn't some invented scoping rule. 00:32:20.540 --> 00:32:23.100 And you can use your formatter on it. 00:32:23.100 --> 00:32:24.780 And you can use mypy on it. 00:32:24.780 --> 00:32:26.440 And you can use all blah, blah, blah. 00:32:26.550 --> 00:32:31.280 You can get IDE assistance on it because it's just Python. 00:32:31.780 --> 00:32:46.000 And so that, from an HTML perspective and a web perspective, we're trying to move from PSP, JSP, PHP-style templating as a separate non-Python concern over into this new world. 00:32:46.260 --> 00:32:47.420 Dave, how did I do on that? 00:32:47.460 --> 00:32:47.980 Do you buy what 00:32:47.980 --> 00:32:48.540 I just said? 00:32:48.540 --> 00:32:49.360 I absolutely buy it. 00:32:49.380 --> 00:33:01.660 And like Paul mentioned, that's sort of how I came into this crazy rollercoaster ride, too, which is I had been working with a number of nonprofits over the last couple of years, building Python backends, doing a lot of front-end development with Python code. 00:33:02.120 --> 00:33:07.980 and feeling like, and in particular, one of the projects I worked on a couple years ago used HTMX. 00:33:08.020 --> 00:33:10.420 I think it was one of my first experiences with HTMX. 00:33:10.960 --> 00:33:17.820 And for those who haven't used it, you often write big templates and then occasionally you need to send lots of little blobs of HTML back. 00:33:18.260 --> 00:33:28.160 And it really starts to get difficult to use a tool like Jinja or a tool like Django templates to produce lots of little blobs of HTML while still keeping everything cleanly organized. 00:33:28.380 --> 00:33:32.520 You end up with lots of sort of include statements or Jinja macros. 00:33:33.120 --> 00:33:41.260 And those are great, powerful features, but they aren't quite as powerful as what Paul was saying, which is the full generality of the Python programming language to begin with. 00:33:41.820 --> 00:33:49.940 And so, you know, we started resorting to using HTML builders like HTTPY in my case, but there are a few others, Dominic and others. 00:33:51.200 --> 00:33:59.940 And those felt great, but they also felt to me like what building web stuff felt like in the JavaScript ecosystem circa 2010, right? 00:34:00.440 --> 00:34:05.920 Before tag template strings came along and ultimately in the JavaScript world before JSX came along as well. 00:34:07.320 --> 00:34:10.700 And so it did feel like there was really an opportunity to revisit that question. 00:34:10.820 --> 00:34:18.419 And that's sort of how I found Jim and Paul, who were thinking about this stuff and have been thinking about this stuff for far longer than I in the Python ecosystem. 00:34:19.260 --> 00:34:19.800 Yeah, very neat. 00:34:19.830 --> 00:34:21.860 I pulled up an example from Vue.js. 00:34:22.480 --> 00:34:24.799 And Dave, you mentioned HTMX. 00:34:25.780 --> 00:34:32.120 And one of the big ideas that Carson Gross from HTMX promotes is locality of behavior. 00:34:32.520 --> 00:34:36.980 Like I should be able to look kind of here on my editor and see all the stuff's going on. 00:34:37.080 --> 00:34:41.800 There shouldn't be four different places and then a convention that pulls in a fifth place that then makes a thing happen. 00:34:42.340 --> 00:34:47.560 And there's a lot of that in the JavaScript world of like, well, here's your behavior. 00:34:47.740 --> 00:34:54.980 And literally, here's the fragment of HTML that we're going to work on with capturing values and different substitutions and stuff. 00:34:55.100 --> 00:34:59.900 And it feels like new templating, and by templating, you're the one who said this silver letter, right? 00:35:00.220 --> 00:35:00.480 Yeah. 00:35:00.740 --> 00:35:11.300 New templating options like Chameleon 2 or Jinja 3 or whatever could come along and build on the ideas using some of the things here. 00:35:11.580 --> 00:35:12.340 Yeah, absolutely. 00:35:12.540 --> 00:35:18.380 And I'm really hoping we see an explosion of that as after Python 3.14 ships out the door. 00:35:18.800 --> 00:35:26.460 So a lot of this work that the three of you plus others, I want to be super clear that there are other folks at the top of this PEP here. 00:35:26.720 --> 00:35:27.060 Yes. 00:35:27.880 --> 00:35:30.060 About this who have also put a lot of work into it. 00:35:30.840 --> 00:35:31.680 Yeah, not just at the 00:35:31.680 --> 00:35:36.620 top of the pep, but also, of course, the broader Python community in the discussions without which. 00:35:37.860 --> 00:35:40.740 And then Paul mentioned the discussions are longer than for any PEP. 00:35:41.100 --> 00:35:44.040 But without that community feedback, I don't think we have landed 00:35:44.040 --> 00:35:44.800 where we are now. 00:35:45.920 --> 00:35:48.360 So if I print this, how long would this be? 00:35:49.140 --> 00:35:49.820 How many pages? 00:35:51.380 --> 00:35:56.440 206 pages to print the discussion of the TagStrings announcement. 00:35:56.490 --> 00:35:57.480 And that was the first. 00:35:57.490 --> 00:35:58.220 There were two discussions. 00:35:59.300 --> 00:35:59.800 Even better 00:35:59.800 --> 00:36:00.580 than Novella. 00:36:02.760 --> 00:36:03.460 Yeah, that's incredible. 00:36:03.900 --> 00:36:04.300 Also 00:36:04.300 --> 00:36:04.560 great 00:36:04.560 --> 00:36:09.640 feedback in other locations as well that we were also really trying to respond to. 00:36:10.210 --> 00:36:12.360 They were talking about Reddit or Hacker News. 00:36:14.980 --> 00:36:17.400 And a lot of credit to Jim on this. 00:36:17.460 --> 00:36:22.560 in the first round, Jim was really about lazy evaluation. 00:36:23.120 --> 00:36:34.200 And it was part of bigger ideas about inside out or outside in rendering and streaming and generators and a lot of things connected in his brain about it. 00:36:34.520 --> 00:36:41.640 And there was a lot of practical pushback, including Astral, about, hey, we're going to struggle to statically analyze that for Ruff. 00:36:41.960 --> 00:36:47.420 And Jim thought about it pretty hard and talked with Dave a lot and talked with others about 00:36:47.440 --> 00:37:08.280 rolled that back. Wow. So there's a difference between, there's a difference here between lazy, which is they're evaluated eagerly, these t-strings, but maybe, and async, right? So can we do async stuff on our strings? Like you have to call a function given a template to render text. That seems like you could just write that, yeah? 00:37:08.500 --> 00:37:42.300 Let me unmute myself. So yeah, I mean, the basic thing here is that these are expressions that can be evaluated, right? And so just because you have a, you know, I'll go for something that's even, you know, broader than this. You look at something like, you know, common pattern like Django's query set, right? So it's lazily evaluated until you actually go and actually look at its contents. A query doesn't even happen, right? In terms of against the underlying SQL engine that you're using. 00:37:43.380 --> 00:37:49.560 And in any event, the point is that we can have laziness where we Lambda wrap it. 00:37:49.690 --> 00:37:53.520 That was the original idea, and there's a lot of potential value in that. 00:37:54.200 --> 00:38:01.840 But there's also this aspect that, in general, the Python community has come up with a number of ways to incorporate laziness. 00:38:02.560 --> 00:38:09.600 And specifically through maybe it's an interval, Maybe it's a query set that is also inevitable. 00:38:09.920 --> 00:38:11.840 Maybe it's through the use of async expressions. 00:38:12.120 --> 00:38:20.620 These are all expressions that can be passed around and then used by, you know, something that is evaluating with respect to that. 00:38:21.680 --> 00:38:23.960 So t-strings don't change any of that, right? 00:38:24.340 --> 00:38:38.020 Because, you know, if you have that expression and it's been evaluated, but it's lazily, it's been lazily so, it can still be used for however you're going to work with that template in the function that operates on it. 00:38:39.880 --> 00:39:01.060 And I think this is just going to get at most of the things that I was thinking about when we were originally looking at this from this more lazily done way without the typing issues that ultimately we decided would make it too difficult to work with. 00:39:01.720 --> 00:39:06.480 So I think this is just something where we looked at what is the Python ecosystem? 00:39:07.020 --> 00:39:08.360 How have we solved these problems? 00:39:09.760 --> 00:39:25.640 and even though there was, you know, I really wanted to go and have something that basically would allow for maybe some greater functionality along, you know, doing like a deferred or lazy type capability implicitly, you know, that can be something else. 00:39:26.140 --> 00:39:29.940 We can bring, you know, there are discussions around like bringing in macros. 00:39:30.160 --> 00:39:38.680 It's, you know, you could implement that using coding on your file. 00:39:39.180 --> 00:39:40.340 I don't know where that goes. 00:39:40.780 --> 00:39:43.440 It might even interface with what we've done with t-strings. 00:39:43.780 --> 00:39:51.620 But the important thing is that you don't have to bring all that in in order to go and benefit from what we're doing with this. 00:39:52.080 --> 00:39:52.160 And 00:39:52.160 --> 00:39:52.500 by 00:39:52.500 --> 00:40:02.700 simplifying what we've done, I think we've, you know, come up with something that works a lot better. And I really valued the great feedback we had from the community as far as that was concerned. 00:40:02.800 --> 00:40:33.080 Yeah, thanks. One of the things I hear a lot mentioned throughout the conversations and the PEP and stuff is DSLs. So a domain specific language and SQL is kind of a domain specific language. But I think a lot of times people are thinking something I make that is really simple, right? Maybe I want to make a language to talk to simple robots, right? And I want to use this to construct maybe a way to talk to it that's way simpler, but easier to parse because you can say, well, here's where the where piece went or whatever, right? 00:40:33.240 --> 00:40:35.820 You can pull them out of the interpolations and the values and stuff. 00:40:36.100 --> 00:40:39.960 Can you guys talk to maybe some examples of what you had in mind or what might be possible there? 00:40:40.220 --> 00:40:41.100 This is good to me. 00:40:41.980 --> 00:40:49.240 So the Python has been a very popular tool for constructing two types of DSLs. 00:40:49.580 --> 00:41:00.760 One would be like the internal DSL that you see in Pydantic or SymPy, that sort of thing, where it's basically taking advantage of operator overloading. 00:41:00.990 --> 00:41:01.980 So let's put that aside. 00:41:02.420 --> 00:41:11.900 We'll look at the other version, which is this external DSL, where we think about, again, canonically HTML, SQL being pretty large targets. 00:41:12.350 --> 00:41:18.320 But if you look at the PyParsing project, you'll see, I don't know, how many dozens of languages it supports. 00:41:18.740 --> 00:41:29.040 Not to mention the fact that it's straightforward to write your own grammar in it and parse it into an abstract syntax tree. 00:41:30.260 --> 00:41:41.660 Yeah, I mean, it's just like, as it says here, the use of parsing expression grammars, you know, really makes it very straightforward to write a cursor. 00:41:42.860 --> 00:41:58.460 So I highly recommend anyone who's like interested in writing their own toy language or maybe have greater ambitions, look into tools like this, because I think this is one of the fantastic advantages we have in the Python community is we have really great libraries like this that are widely used. 00:41:59.490 --> 00:42:06.260 And so for your example of writing something that would interface with a robot, absolutely, absolutely. 00:42:06.500 --> 00:42:08.800 That's something that you could express. 00:42:09.190 --> 00:42:17.320 And you think about, would that potentially be even something where it could be useful for education, for example? 00:42:17.760 --> 00:42:20.020 And how would it work with, again, t-strings? 00:42:20.260 --> 00:42:25.100 Well, again, you would basically say there's this domain of things that we know from the Python space. 00:42:25.859 --> 00:42:31.080 We're computing maybe some velocity that we want the robot to move at. 00:42:31.440 --> 00:42:39.180 We're computing which color of brick that we want to pick up or whatever it happens to be. 00:42:40.060 --> 00:42:46.060 And we can basically say that that's something that's happening in our Python code directly. 00:42:46.580 --> 00:42:50.000 And then there's this language that we're using to talk to the robot. 00:42:50.000 --> 00:43:06.580 Okay. And what it looks like in terms of the t-strings is you basically are saying, okay, I'm going to go and parse this language fragment with some parser that can be made to use placeholders that will work with interpolations. 00:43:06.980 --> 00:43:22.880 And I'm going to parse it. I'm going to get an abstract syntax tree out of that. I'm going to use that to then evaluate how I'm going to go and say, you know, send in a number or color or other information to that toy language or more ambitious language. 00:43:23.340 --> 00:43:32.540 and then send out whatever is necessary in order to complete that communication with the system that's implementing that. 00:43:32.800 --> 00:43:38.040 So it's going to be great for people who really love languages and want to play with them. 00:43:38.240 --> 00:43:40.100 And again, I would start with something like PyParsing. 00:43:40.420 --> 00:43:43.660 That was a great example of the type of tool you could use here. 00:43:43.840 --> 00:43:44.160 Excellent. 00:43:44.410 --> 00:43:46.900 Yeah, I'll put that link in the show notes so people can check it out. 00:43:47.540 --> 00:43:56.760 Yeah, maybe bringing it all back home for a second or maybe just because I've got my head wrapped in building slide deck for a lightning introduction, lightning talk introduction to t-strings. 00:43:57.540 --> 00:44:09.080 But, you know, a common use case here when you're writing code that takes a template is not returning a string, but as Jim is kind of deeply hinting at here, parsing and returning some kind of abstract syntax tree. 00:44:09.130 --> 00:44:29.780 So in the HTML case, and you can actually find examples of this, for example, in the PEP 750 examples repository, there's an HTML function there and it has a bunch of nice features, but you're returning an HTML element back from the code that processes the T-string, you don't, in fact, have to grab a string out of a T-string right away or ever if you don't want to. 00:44:30.280 --> 00:44:35.340 So there's an immense amount of flexibility here that we're excited to see people use. 00:44:35.720 --> 00:44:39.180 Yeah. Dave, under your account on GitHub, Dave Peck. 00:44:39.260 --> 00:44:39.600 Needs 00:44:39.600 --> 00:44:40.000 to move. 00:44:40.780 --> 00:44:43.900 You know what? It's fine. It's just as good as anywhere. 00:44:44.600 --> 00:44:47.440 You have a bunch of examples of things you might do 00:44:47.440 --> 00:44:48.920 with 00:44:48.920 --> 00:44:49.280 these. 00:44:49.540 --> 00:44:50.980 and one of them is HTML. 00:44:51.740 --> 00:44:54.220 People can see how that might work and so on. 00:44:54.340 --> 00:44:56.300 And what are some of the other notable ones in here? 00:44:56.400 --> 00:44:57.380 I know I was looking through this earlier. 00:44:57.720 --> 00:45:02.940 Well, we wanted to show some basic examples like, hey, t-strings have a syntax that looks a lot like f-strings. 00:45:03.180 --> 00:45:05.100 How could you build f-strings on top of t-strings? 00:45:05.280 --> 00:45:15.920 So there is an F paren-paren method that's implemented here that just kind of helps you understand, okay, I'm writing dynamic code to do the thing that f-strings would have done at compile time anyway. 00:45:17.280 --> 00:45:20.000 We also have a structured logging example. 00:45:20.150 --> 00:45:29.020 And I'm excited about this, you know, structured logging that Python has shipped a logging cookbook for a long time since the Python 2.something era. 00:45:29.730 --> 00:45:38.720 And one of the examples in that logging cookbook is structured logging, by which we mean like, hey, I want to write out a sentence or two that people can understand, that humans can read. 00:45:39.070 --> 00:45:42.040 But I also have some values that I'm substituting in that sentence. 00:45:42.170 --> 00:45:45.440 And I'd really like that to be written out in some schema compliant way. 00:45:46.560 --> 00:46:01.700 And with t-strings, you can kind of do that in a really elegant way, which is to say you write the T-string once, you send it to some kind of method that expects t-strings on logging, and it emits basically the equivalent of an F-string. 00:46:01.820 --> 00:46:03.160 So that's the human readable bit. 00:46:03.360 --> 00:46:09.160 And then maybe it uses JSON or something to emit a structured output to a different log stream entirely. 00:46:09.740 --> 00:46:19.860 So one of the examples in the PEP and also in this PEP 750 repo is, you know, we send the human readable stuff to standard out and we send the machine readable stuff to standard error. 00:46:20.540 --> 00:46:24.760 And you can imagine, you know, your logging system is going to redirect those somewhere else over 00:46:24.760 --> 00:46:24.900 time. 00:46:24.960 --> 00:46:25.120 Yeah. 00:46:25.590 --> 00:46:30.360 I mean, the example here, you got standard error, but you could easily do a document database with JSON as well. 00:46:30.510 --> 00:46:33.000 And then put an index on action and say, show me all the actions 00:46:33.000 --> 00:46:34.180 taken 00:46:34.180 --> 00:46:36.820 that have this commonality in it. 00:46:36.890 --> 00:46:37.020 Right. 00:46:37.220 --> 00:46:43.400 and do a querying, oh, bam, rather than really error-prone, like substring matching of text or whatever, right? 00:46:43.560 --> 00:46:45.200 Yeah, and I'm really excited about it. 00:46:45.200 --> 00:46:53.800 You write the T-string once, and you get the benefit of both the human readable and the structured schema-compliant output, and that's really exciting to me. 00:46:54.800 --> 00:46:54.860 Yeah, 00:46:55.240 --> 00:46:57.980 and I guess if you use Postgres, you could just put it in a JSON field as well. 00:46:58.300 --> 00:47:00.660 Oh, yeah, we call that mullet 00:47:00.660 --> 00:47:01.520 schema, right? 00:47:01.940 --> 00:47:06.340 It's a business up front and partying back where the last column on every table is a JSON field. 00:47:07.000 --> 00:47:07.640 I've never heard that. 00:47:07.820 --> 00:47:08.640 That's incredible though. 00:47:09.040 --> 00:47:12.220 It's like, yeah, we look real formal, but don't look back there. 00:47:14.420 --> 00:47:15.420 Got it in the ponytail today. 00:47:15.820 --> 00:47:16.080 Yeah. 00:47:16.260 --> 00:47:16.600 Amazing. 00:47:18.900 --> 00:47:19.080 Okay. 00:47:19.680 --> 00:47:24.820 One thing I wanted to cover, there's a really interesting thing from somewhere in here. 00:47:24.920 --> 00:47:25.960 I have pulled this up, I believe. 00:47:26.160 --> 00:47:26.940 I'll just go to the PEP. 00:47:27.340 --> 00:47:31.000 And the PEP, there's a section that talks about how to teach this. 00:47:31.220 --> 00:47:39.180 And I think that that's, there's just a couple of ideas here that I think would make it really interesting for helping people understand better, right? 00:47:39.360 --> 00:47:45.500 Speaking to developers or maybe people who build libraries like web frameworks or logging libraries or something. 00:47:45.860 --> 00:47:51.960 Who wants to kind of give us a few of the ideas here that just maybe like, I know we touched on some of them a little bit. 00:47:52.040 --> 00:48:00.800 Yeah, I mean, I'm happy that I kind of stepped through the basics here, which is, you know, we touched on the fact that the syntax of t-strings and f-strings is essentially identical. 00:48:01.560 --> 00:48:07.520 Anytime you have an F, you can substitute with a T, but the result, the evaluated result is entirely different. 00:48:07.720 --> 00:48:12.500 You get a string or a template, and we've kind of talked about all the reasons why you might want to do that. 00:48:12.960 --> 00:48:28.580 I guess the key thing for developers to understand, and I'm going to divide developers into two groups here, those who use t-strings and pull in like an HTML or a SQL library, for example, and don't really think much about what's going on under the hood. 00:48:29.030 --> 00:48:35.180 For them, all they need to know is, hey, you write T of something and you send it to your SQL library and it's safe. 00:48:35.980 --> 00:48:38.460 And you don't really need to think much more about it than that. 00:48:38.760 --> 00:48:47.980 And then, of course, we had, sorry, but we had things like literal strings and other stuff in the type system that kind of tried to make type checkers check and 00:48:47.980 --> 00:48:49.360 catch when that would happen. 00:48:49.740 --> 00:48:56.260 Right. But this is more runtime catching because of the way it operates rather than, hey, it's a bad idea to do that. 00:48:56.360 --> 00:48:57.940 But, you know, Python typing can be ignored. 00:48:58.220 --> 00:48:58.280 So, 00:48:58.840 --> 00:49:01.440 yeah, it's probably worth mentioning the limits of that. 00:49:01.500 --> 00:49:08.680 I mean, template and interpolation, which are new types that ship with Python 3.14, are ones that you can cons up at runtime directly. 00:49:09.160 --> 00:49:10.720 You don't need to start with a literal. 00:49:11.230 --> 00:49:18.080 And so you can, of course, as a developer, do all kinds of goofy stuff and cons up all sorts of malicious templates if you want to. 00:49:18.460 --> 00:49:30.880 But generally speaking, if you're working from literals, which we sort of expect is the very common case, and you're using libraries that know about this new feature when Python 3.14 ships, generally speaking, you're staying on the safe side. 00:49:31.060 --> 00:49:32.740 You're staying in the bright, well-lit path. 00:49:33.380 --> 00:49:33.520 Yeah. 00:49:33.640 --> 00:49:44.020 One of the ideas I like to think about in APIs and design of software is like falling into the pit of success or falling into the pit of despair. 00:49:44.340 --> 00:49:49.420 You want to make it so the natural action is to fall into the pit of success and you've got to work your way out of there. 00:49:49.540 --> 00:49:49.900 You know what I mean? 00:49:50.040 --> 00:49:51.120 Yeah, you have to work hard to get there. 00:49:51.260 --> 00:49:51.340 Yeah, 00:49:51.400 --> 00:49:52.260 hopefully we've 00:49:52.260 --> 00:49:53.320 found a nice balance there. 00:49:53.580 --> 00:49:55.000 Yeah, it seems like it has. 00:49:55.480 --> 00:49:55.660 Yeah, I 00:49:55.660 --> 00:50:02.080 mean, I think from a teaching it perspective, you know, the pit of despair is so easy to fall into with f-strings, right? 00:50:02.500 --> 00:50:08.360 You know, so your structure logging, you know, I'm sorry, using f-strings in your logging is like, oh, I inadvertently log some passwords. 00:50:09.020 --> 00:50:10.220 Well, that's unfortunate, right? 00:50:10.720 --> 00:50:14.360 Or I, you know, I'm using f-strings with a SQL statement. 00:50:14.530 --> 00:50:16.740 It's like, oh, that really worked until it didn't. 00:50:17.010 --> 00:50:20.880 And so it's very easy to go down that into that pit of despair as you're describing. 00:50:21.360 --> 00:50:30.560 Whereas we're hopefully making it, you know, something where you have to work a little bit, know what you're doing, in fact, in order to go and actually do something that's bad. 00:50:31.580 --> 00:50:41.440 So, you know, I'm sure that, you know, someone can show me, you know, a couple steps that, you know, make it straightforward to get into that pit of despair. 00:50:42.060 --> 00:50:45.400 But I don't think it would be still the most obvious thing to do. 00:50:45.760 --> 00:50:50.400 So from a teaching perspective, we want to ensure that the most obvious thing to do is the right thing to do. 00:50:50.720 --> 00:51:00.800 And, you know, people can build libraries, you know, an HTML function or whatever in order to ensure that is, you know, going to work with that right path. 00:51:01.140 --> 00:51:01.580 But there's more. 00:51:01.580 --> 00:51:12.780 I think, Paul, you know, if you wanted to go and just how to teach this, I think part of this is just like, again, things like IDE integration and things like, you know, working with lenders and whatnot. 00:51:13.500 --> 00:51:15.540 That's also very exciting in terms of what can be done. 00:51:16.120 --> 00:51:17.800 And for me, that's kind of the exciting part. 00:51:17.820 --> 00:51:25.240 but there's a side about really lowering the bar for writing these functions that handle a template. 00:51:25.640 --> 00:51:27.700 You're not going to do anything with a template yourself. 00:51:28.000 --> 00:51:29.980 You're going to hand it to a function that's going to do something. 00:51:30.220 --> 00:51:35.640 And it's going to return a stringable, not a string, something that can be made later into a string. 00:51:36.020 --> 00:51:43.200 But it's the people on the other side that are going to be creating the values and the content and all that kind of stuff. 00:51:43.270 --> 00:51:45.680 And we have a real chance here to help them. 00:51:45.980 --> 00:51:50.060 We're not going to talk about double curly braces or single curly braces for the rest of time. 00:51:50.360 --> 00:51:52.380 It's single curly, just that alone. 00:51:53.060 --> 00:51:59.740 And what goes in there isn't going to be some invented language with a pipe that you send to safe or whatever. 00:51:59.840 --> 00:52:03.460 And you got to go memorize all these rules about how do I call a macro. 00:52:03.920 --> 00:52:12.160 It's just Python, which then means IDEs and tools and linters and formatters and type checkers all get to play a game. 00:52:12.600 --> 00:52:16.900 Go to mypy and file a ticket asking for type checking on Jinja. 00:52:17.260 --> 00:52:19.300 There is a ticket already and you can see their comments. 00:52:19.820 --> 00:52:21.020 They're not that interested. 00:52:21.500 --> 00:52:23.300 Same thing for a lot of other tools. 00:52:23.820 --> 00:52:33.700 But if they support 3.14, they support template strings and they support f-strings and they support this kind of everything because everything is just where it's supposed to be. 00:52:34.000 --> 00:52:39.420 And if I can go a little bit, Dave, is it okay if I go a little bit further on this riff about tooling? 00:52:39.860 --> 00:52:41.580 Let's see, you've got some points to make. 00:52:41.760 --> 00:52:42.460 Sorry, I'm on a roll. 00:52:43.300 --> 00:52:44.740 I'll try to wrap it up, I promise. 00:52:46.040 --> 00:52:55.740 This idea of a big ecosystem of tooling and all of that will give us a developer experience that's competitive again. 00:52:56.200 --> 00:52:58.900 All of these tools can start pitching in. 00:52:59.480 --> 00:53:00.700 I'm with the PyCharm team. 00:53:00.970 --> 00:53:04.900 Because this is f-strings with a T, they did it just like that. 00:53:05.280 --> 00:53:13.720 Dave did a fork of black where he got T string support basically just like that because it was a T instead of an F. 00:53:14.200 --> 00:53:18.720 Then we can get into some more interesting things like an HTML templating library. 00:53:18.960 --> 00:53:25.280 We are very fortunate in the world of Python to have Andrea over from JavaScript on the PyScript team. 00:53:25.620 --> 00:53:32.440 He's written 400,000 variations of JavaScript templating engines including tag template literals. 00:53:32.480 --> 00:53:32.640 He 00:53:32.640 --> 00:53:33.320 knows everything. 00:53:33.820 --> 00:53:36.920 He contributed a lot to this PEP such as that alternating thing. 00:53:37.280 --> 00:53:42.740 He's creating an HTML templating language that is browser first. 00:53:43.280 --> 00:53:48.140 Michael, you had a Vue.js up earlier that had like at click. 00:53:49.100 --> 00:53:58.020 There's going to be a lightning talk at PyCon about showing this in PyScript where something can run on the server and in the client and it's 00:53:58.020 --> 00:53:58.320 nuts. 00:53:58.530 --> 00:53:59.840 The whole thing is just... 00:54:00.460 --> 00:54:03.320 Server rendered templates, but also client-side stuff. 00:54:03.650 --> 00:54:04.040 Yeah, yeah, 00:54:04.280 --> 00:54:04.680 yeah, yeah. 00:54:05.380 --> 00:54:18.760 So there is a chance for us in the world of Python, it doesn't have to be our spelling, but if we can agree to structure and intermediate representations, Dave has ideas about how HTTPY could play ball. 00:54:19.120 --> 00:54:21.280 They can make components that we can consume. 00:54:21.350 --> 00:54:23.160 We can make components that they can consume. 00:54:23.500 --> 00:54:33.960 I'm really bullish on how we can change the developer experience in web development and more to be modern Python with tooling. 00:54:34.590 --> 00:54:34.800 Dave. 00:54:35.000 --> 00:54:36.320 I'm here for it. I'm here for it, Paul. 00:54:36.810 --> 00:54:38.440 Yeah, I'm just going to give you a what what here. 00:54:39.160 --> 00:54:39.280 Yeah. 00:54:41.020 --> 00:54:41.180 Yeah. 00:54:41.730 --> 00:54:51.800 I think if we really can unlock a language that works well on the front end, I know PyScript's come a long way, but I feel like we need a view-like thing, right? 00:54:52.100 --> 00:54:52.200 And 00:54:52.200 --> 00:54:52.900 it sounds like 00:54:52.900 --> 00:54:53.980 work is being done. 00:54:54.740 --> 00:54:55.280 I mean, 00:54:55.320 --> 00:54:59.980 if that comes along, there's going to be a lot of people that go, wait, we don't have to do JavaScript? 00:55:00.210 --> 00:55:01.220 Are you serious here? 00:55:01.460 --> 00:55:02.520 That would be pretty amazing. 00:55:02.960 --> 00:55:07.220 Just throw in your 100K MicroPython implementation of PyScript and 00:55:07.220 --> 00:55:07.980 go off 00:55:07.980 --> 00:55:08.280 to the races. 00:55:08.580 --> 00:55:08.920 Go ahead, Jim. 00:55:09.220 --> 00:55:22.980 Yeah, I was just going to say, and one other nice thing about t-strings and the fact that they look a lot like f-strings is that it's going to be a straightforward thing for us to, or I shouldn't say for us, but I think the community. 00:55:24.240 --> 00:55:33.200 I think there will be plenty of people who can work on this, fortunately, to incorporate t-strings into MicroPython. 00:55:33.590 --> 00:55:45.420 And now you, instead of having something that requires a somewhat heavier download in terms of CPython on the client side with PyScript, you can use MicroPython for that. 00:55:46.140 --> 00:55:46.960 I looked into it. 00:55:47.130 --> 00:55:47.760 It looks straightforward. 00:55:48.380 --> 00:55:52.360 I hope that we will see that development happen sooner than later. 00:55:52.720 --> 00:56:04.020 So a lot of opportunities to go and mix together client side and server side in some really interesting and very cool ways going forward with this work. 00:56:04.500 --> 00:56:09.060 What an interesting angle to say, we'll add t-strings to MicroPython. 00:56:09.580 --> 00:56:10.360 Yep, and keep that. 00:56:10.400 --> 00:56:10.620 So that 00:56:10.620 --> 00:56:13.780 it round trips to the front end of the browser in an efficient way. 00:56:14.260 --> 00:56:14.500 Yeah. 00:56:14.580 --> 00:56:14.700 Yeah. 00:56:15.040 --> 00:56:19.980 We've got a bunch of sprint days coming up with PyCon, so you never know. 00:56:21.240 --> 00:56:21.460 Okay. 00:56:21.500 --> 00:56:22.860 But Michael, 00:56:23.040 --> 00:56:31.580 when you mentioned that MicroPython is about 100K, which to my ears as an old school web person sounds huge, but also really tiny these days. 00:56:32.020 --> 00:56:40.280 Like when you build, when you do the default Next.js app install, which literally does nothing but ship a static looking page to you. 00:56:40.390 --> 00:56:45.060 Although, of course, static includes a whole bundle of React and other stuff with Next.js these days. 00:56:45.620 --> 00:56:46.920 That's about 130K. 00:56:47.270 --> 00:56:49.680 And that doesn't include an implementation of Python. 00:56:50.560 --> 00:56:50.820 Yeah. 00:56:50.860 --> 00:56:51.420 It's 00:56:51.420 --> 00:56:52.060 kind of amazing. 00:56:52.340 --> 00:56:55.640 Yeah, and I think it's pretty comparable to other things. 00:56:56.230 --> 00:56:58.840 I'm trying to poke around and find some examples. 00:56:59.200 --> 00:57:04.540 But yeah, I think 100K is certainly doable on a CDN and so on. 00:57:04.760 --> 00:57:05.340 It's a sweet spot. 00:57:05.480 --> 00:57:05.620 Yeah. 00:57:06.300 --> 00:57:06.540 Hey, 00:57:06.640 --> 00:57:07.680 Michael, I got one for you. 00:57:08.060 --> 00:57:11.980 And this is one that Jim and I started talking about and others piped in. 00:57:12.080 --> 00:57:16.260 Kudai, who's also working on this project, is doing stuff in this field. 00:57:17.000 --> 00:57:23.840 LLMs and code that needs to generate good LLM-generated results. 00:57:24.440 --> 00:57:38.480 If you had a template language that was closer to the language of Python and could be analyzed as such, and all the LLM and RAG tricks that people are applying to not just get code, but to get good quality code. 00:57:38.820 --> 00:57:47.760 Is this a moment where we could invent a web development story for Python that wasn't just cool because it was browser first? 00:57:48.090 --> 00:57:53.660 It was cool because it anticipates AI and generated code. 00:57:54.620 --> 00:58:00.740 You know, if you can infer types and things like that because you can look into the structure of the template. 00:58:01.320 --> 00:58:01.560 Yeah. 00:58:01.620 --> 00:58:02.060 and 00:58:02.060 --> 00:58:09.700 know things and they are Python rules inside the curly braces instead of invented stuff, you might have a better shot at machinery. 00:58:10.000 --> 00:58:10.980 Jim, what do you think? 00:58:11.010 --> 00:58:12.160 You had a lot to say on this. 00:58:12.420 --> 00:58:21.400 Yeah, I mean, I think a lot of people are looking at stuff around like in-context learning with how they work with prompts and everything. 00:58:22.760 --> 00:58:38.860 I do think that if I'm going to send a bunch of examples to like some sort of, you know, a mini shot, but I guess a few number of shots learning, it would be really nice to do it in a very structured way and really have good support for that. 00:58:39.140 --> 00:58:44.540 And so if you look at, you know, how people typically do this, well, they emit f-strings. 00:58:45.140 --> 00:58:46.360 And I'm sure it works most of the time. 00:58:46.660 --> 00:58:47.960 I just want it to work all the time. 00:58:49.160 --> 00:59:00.560 And so I think, you know, having something that can, you know, taint that structure, maybe even do some interesting, you know, like there's some stuff around like DSPY or whatever. 00:59:00.590 --> 00:59:11.920 I'm not certain actually how it's pronounced, but it basically does additional rounds of optimizing your in-context learning, prompting in general. 00:59:12.960 --> 00:59:15.320 Having access to that structure might be very helpful for it. 00:59:15.430 --> 00:59:15.900 Who knows? 00:59:16.380 --> 00:59:29.880 I think that there's a lot of interesting opportunities in this space where we maintain this structure, we're able to reflect on it, And then use that for whatever sort of interaction we have with other systems. 00:59:30.620 --> 00:59:33.060 And fundamentally, that's what this supports. 00:59:33.660 --> 00:59:35.560 Because you have access to those Python structures. 00:59:36.220 --> 00:59:39.840 You can figure out what that's supposed to be before you go and send it off to somewhere else. 00:59:40.320 --> 00:59:42.940 So what does that mean in terms of capabilities? 00:59:43.340 --> 00:59:44.040 It's very interesting. 00:59:44.440 --> 01:00:05.520 Paul, when you were talking about typing earlier and then talking about mypy, it just made me realize or think, I guess I thought about it before, But reemphasize that for me, the typing is a communication tool to me, mostly through things like PyCharm, but not 100%, but mostly through the editor saying, here's what it's supposed to be here. 01:00:05.640 --> 01:00:06.820 Here's what this is supposed to do. 01:00:06.870 --> 01:00:09.460 So I don't have to go to definition and try to decipher it. 01:00:10.140 --> 01:00:16.580 And I almost never use mypy or one of these Pyright or Pyre or, you know, you name it, because that's not my goal. 01:00:16.700 --> 01:00:21.280 My goal is to add typing so that I can stay out of the docs, except when I really must. 01:00:21.600 --> 01:00:26.520 And the same applies to what you share with chat and agenda code generators. 01:00:26.950 --> 01:00:33.640 They can look at those types and they can see much more information and it can make them way more accurate and productive, right? 01:00:33.980 --> 01:00:43.360 And I feel like this could communicate more information to them, like you were saying, so they have more structure to work with rather than just, here's a string, I don't know what it is. 01:00:43.480 --> 01:00:44.400 Can I riff on that for a second? 01:00:44.400 --> 01:00:44.740 Yes, riff. 01:00:45.880 --> 01:00:53.720 This is all not news to Dave, who he and I are writing our lightning talks and FlaskCon talk together. 01:00:54.240 --> 01:00:55.800 You're around on Friday afternoon. 01:00:56.120 --> 01:00:56.800 Come see Dave. 01:00:57.040 --> 01:00:57.620 Come see me. 01:00:57.760 --> 01:00:58.940 It's going to be mind 01:00:58.940 --> 01:00:59.200 -blowing. 01:00:59.800 --> 01:01:01.520 Lightning talks are going to be mind-blowing, too. 01:01:01.520 --> 01:01:04.020 Don't they normally publish those videos from FlaskCon as well? 01:01:04.210 --> 01:01:04.680 I think they do. 01:01:05.580 --> 01:01:05.800 Maybe. 01:01:06.140 --> 01:01:06.640 He needs help. 01:01:06.780 --> 01:01:07.000 Okay. 01:01:07.400 --> 01:01:08.160 Well, I'm hoping. 01:01:08.170 --> 01:01:10.620 Poor David is doing 500 jobs at once. 01:01:11.120 --> 01:01:12.580 Everyone support David Lord. 01:01:13.180 --> 01:01:30.140 I'm going to be giving a demo in PyCharm, at least, of T-String support with interpolation autocomplete and navigation and all the PyCharm tricks, but also a experimental plugin that does component support with TDOM. 01:01:30.340 --> 01:01:46.000 So it looks just like JSX, where you pass props to something and it obeys the can do not just autocomplete of the props, But if you're missing a required prop, it will know that because it looks at the function signature of the component. 01:01:46.420 --> 01:01:48.520 And it will match the types of the prop. 01:01:48.580 --> 01:01:51.260 If you pass a string for an int, it will squiggle you. 01:01:51.440 --> 01:02:02.120 In the future, we can go further like a lot of IDs can do and extract components to be standalone, to get big components into small components, all kinds of things. 01:02:02.320 --> 01:02:09.740 Once you get into the world of tooling, you know, you've got typing, you've got signatures, you've got all of these great things. 01:02:09.920 --> 01:02:13.540 mouse over for doc strings and doc hints and help. 01:02:14.120 --> 01:02:14.540 Lots of help. 01:02:14.660 --> 01:02:14.980 That's awesome. 01:02:15.400 --> 01:02:16.540 Well, I'm looking forward to it. 01:02:16.900 --> 01:02:17.860 Guys, we're about out of time. 01:02:18.050 --> 01:02:21.240 I want to wrap this up with one final thought here. 01:02:21.460 --> 01:02:27.740 So speaking to several audiences, let's say two audiences at the moment, give us some advice for potential adopters. 01:02:28.160 --> 01:02:38.140 So if I'm Sebastian from FastAPI or David from FlaskCourt or I'm some other library adopter, SQL, MicroSQLAlchemy, right? 01:02:38.900 --> 01:02:40.320 Or that's audience one. 01:02:40.650 --> 01:02:45.020 Audience two would just be people who thought f-strings were awesome and this is even more awesome. 01:02:45.200 --> 01:02:46.260 They want to try it in their code. 01:02:46.540 --> 01:02:49.420 What are some pitfalls and best practices for these folks? 01:02:49.490 --> 01:02:50.840 And what are the opportunities there? 01:02:51.100 --> 01:02:58.340 Well, I mean, I think, you know, in general, the fact that t-strings exist doesn't mean that f-strings need to disappear tomorrow. 01:02:58.560 --> 01:03:06.320 So I guess that would be the first thought I'd have for the community that isn't actively building libraries that might benefit from T string functionality, which is that the 01:03:06.320 --> 01:03:06.700 tool is 01:03:06.700 --> 01:03:07.180 still useful. 01:03:07.840 --> 01:03:12.140 And in fact, there are many cases where probably what you really want is an f-string rather than a t-string. 01:03:12.760 --> 01:03:13.360 It's exactly 01:03:13.360 --> 01:03:28.700 these cases where you want the interpolations to do something special, whether that's prevent injunction vulnerabilities or, you know, transliterate, you know, a single dictionary into a bunch of attributes in HTML where you might want to start playing with t-strings. 01:03:29.280 --> 01:03:35.440 And there, you know, I think if you're a library developer and you happen to be at PyCon, come say hello. 01:03:35.920 --> 01:03:39.620 we'd love to talk to you and kind of figure out how you're thinking about adopting these. 01:03:39.980 --> 01:03:46.360 I think the biggest one that came up in discussion amongst library developers that I saw was just, wait, how do I type my function? 01:03:46.620 --> 01:03:53.840 So if I'm writing a SQL layer and I've got an execute method, right now that takes a string or maybe it takes, you know, Michael, you mentioned a little string. 01:03:53.900 --> 01:03:57.960 It takes some variety of some special type that my library supports. 01:03:58.500 --> 01:04:00.080 Should I also take a template there? 01:04:00.300 --> 01:04:01.680 Should I allow a union of both? 01:04:02.140 --> 01:04:03.380 Probably that's a foot gun. 01:04:03.540 --> 01:04:06.120 you probably really want to think about separating these things out. 01:04:06.750 --> 01:04:10.200 And so I think we'll see best practices like that kind of emerge over time. 01:04:10.540 --> 01:04:12.560 Yeah, I would add a couple things. 01:04:12.860 --> 01:04:15.360 One, we actually love f-strings. 01:04:16.480 --> 01:04:16.920 When you 01:04:16.920 --> 01:04:25.960 look at the actual code that implements the t-string functionality in terms of like a library, like an HTML function or whatever, what do you find in there? 01:04:26.190 --> 01:04:32.100 Lots of uses of f-strings to actually go and pump out the actual string that you need. 01:04:33.000 --> 01:04:44.480 It's just done in this, you know, disciplined fashion that we can do because we have carefully separated out when the interpolations are being actually evaluated in that context, right? 01:04:45.660 --> 01:05:01.320 Second thing to think about is in terms of like a good best practice would be, you know, if you have a T-string, you know, and you say HTML, well, I don't think HTML should just like do something there or SQL or whatever. 01:05:01.380 --> 01:05:10.240 It should go and allow it to prepare, you know, a document object model or, you know, prepare a SQL query or whatever. 01:05:10.800 --> 01:05:13.920 And then you execute it or render it or whatever. 01:05:14.380 --> 01:05:23.240 So I would differentiate this sort of setup versus, you know, some final rendering would be a typical best practice that certainly I would recommend. 01:05:24.540 --> 01:05:33.880 And there are obviously more, you know, another best practice definitely is at some point, you probably want to think about the optimization of these things, right? 01:05:33.880 --> 01:05:41.980 And so we really put in some thought into how the template strings can be used as a memorization key efficiently. 01:05:43.290 --> 01:05:46.000 So you can look it up in terms of an LRU cache. 01:05:46.360 --> 01:05:52.580 Now, this is no different than if you looked at the internals of, say, the RE module, you know, sports regular 01:05:52.580 --> 01:05:53.000 expressions. 01:05:53.660 --> 01:05:53.820 Yeah. 01:05:54.870 --> 01:06:00.220 You know, there is this, at one point, you actually had to go into RE compile. 01:06:00.980 --> 01:06:06.760 And it's not a bad practice to do it, but if you look internally at it, it actually does the RE compile for you. 01:06:06.810 --> 01:06:13.120 So you don't pay the overhead of running through this Python parse every single time. 01:06:13.760 --> 01:06:14.700 Interesting. I didn't know that. 01:06:15.360 --> 01:06:15.460 Yeah. 01:06:15.460 --> 01:06:15.560 Yeah. 01:06:16.680 --> 01:06:29.780 But the actual implementation of that in terms of running the regular expression is done through this bytecode virtual machine that's specific to regular expressions. 01:06:30.360 --> 01:06:31.260 and can be very efficient. 01:06:31.630 --> 01:06:44.820 So again, we'll see some of these sorts of separations where we'll think about what it means to go and have a fast path where you actually are evaluating this HTML fragment or whatever, or working with SQL. 01:06:45.320 --> 01:06:49.540 And then there's some sort of, well, you have to pay the parse penalty at some point. 01:06:49.980 --> 01:06:57.940 But part of paying that parsing penalty is ensuring that things are done in a safe fashion, being written out in a structured way. 01:06:58.340 --> 01:07:12.340 So that's, you know, more than makes up for it compared to, again, just, you know, just using f-strings and hoping that your SQL statement didn't include, you know, in that interpolation, the Bobby tables evil injection. 01:07:13.320 --> 01:07:14.060 Yeah, excellent. 01:07:14.300 --> 01:07:24.160 For me, I'd say first a shout out to our PEP sponsor and the hero for the second half of all this, Lissandros, has been marvelous. 01:07:25.660 --> 01:07:30.380 getting the implementation and shaping in our interface to the rest of the core team and all that kind of stuff. 01:07:30.930 --> 01:07:33.740 Really fast turnaround, really joy to work with. 01:07:34.260 --> 01:07:37.900 Dave and Lissandro spent a lot of time ironing out all the little things. 01:07:38.260 --> 01:07:44.700 I think about this whole path since Guido and Jim sat down at a PyCon like three years ago on the implementation. 01:07:44.970 --> 01:07:49.340 I think it's been, this will be like the fourth PyCon since this whole thing first started. 01:07:50.380 --> 01:07:58.400 And Jim and Guido kind of laid the groundwork for where we are right now, which is t-strings is just the start. 01:07:58.630 --> 01:08:00.840 t-strings by itself ain't that much. 01:08:01.150 --> 01:08:07.960 And I think, Jim, you made some decisions to intentionally defer to future PEPs some of the things. 01:08:08.880 --> 01:08:14.140 Jim just said about these functions that don't immediately render. 01:08:14.230 --> 01:08:17.859 They prepare an intermediate representation that might later render. 01:08:18.220 --> 01:08:20.600 For me, that's my interest in this PyCon. 01:08:21.160 --> 01:08:22.120 Let's build a community. 01:08:22.600 --> 01:08:33.759 Let's build a community around interoperability so HTPy doesn't have to spell things our way, but we can talk to each other because we agree on a node interface or something like that for a DOM representation. 01:08:34.520 --> 01:08:38.100 The front-end world has gotten great value out of pluggability. 01:08:38.460 --> 01:08:45.319 The Vite system, for example, is a processing chain with a documented intermediate representation. 01:08:45.640 --> 01:08:48.819 It's easy to write a plug-in to go grab that and hack on it. 01:08:48.819 --> 01:08:50.859 You want to turn everything into a relative URL? 01:08:51.430 --> 01:08:56.400 Write a little plug-in, put it in the chain, and you'll be handed something that lets you operate on things. 01:08:57.180 --> 01:08:59.540 We can do something great together. 01:08:59.540 --> 01:09:06.020 We don't all have to do the XKCD to invent a new standard to replace all the other standards. 01:09:06.580 --> 01:09:08.299 We can still work with Jinja. 01:09:08.400 --> 01:09:14.580 We could still work with HTTPY and some of these other things, and hopefully we'll see some of that at PyCon. 01:09:14.819 --> 01:09:15.880 Awesome. Thank you, guys. 01:09:16.200 --> 01:09:21.060 And we're specifically recording this on a time frame that hopefully... 01:09:21.299 --> 01:09:22.299 Thank you so much, Michael. 01:09:22.600 --> 01:09:28.520 If people are dutiful and on top of their listening, we'll listen to this right before they go to PyCon. 01:09:28.670 --> 01:09:33.779 So I would like to encourage them to reach out to all of you and maybe go to some of the lightning talks. 01:09:34.020 --> 01:09:35.560 And if they have ideas, participate. 01:09:35.940 --> 01:09:36.560 Because now is the time. 01:09:36.779 --> 01:09:38.040 Thanks, Michael, for doing this. 01:09:38.049 --> 01:09:40.500 And we're excited to meet everybody at PyCon who's heading out that way. 01:09:40.799 --> 01:09:40.880 Yeah. 01:09:41.160 --> 01:09:41.560 Paul, you're welcome. 01:09:41.710 --> 01:09:42.720 And you too, Dave. 01:09:43.859 --> 01:09:46.180 Jim, Dave, and Paul, thank you all for being here. 01:09:46.480 --> 01:09:46.799 See you later. 01:09:47.180 --> 01:09:47.279 All 01:09:47.279 --> 01:09:47.420 right. 01:09:47.680 --> 01:09:48.359 Thanks for having us. 01:09:48.759 --> 01:09:49.000 Thank you. 01:09:49.400 --> 01:09:49.580 Bye-bye. 01:09:50.940 --> 01:09:53.359 This has been another episode of Talk Python To Me. 01:09:54.220 --> 01:09:55.060 Thank you to our sponsors. 01:09:55.540 --> 01:09:56.760 Be sure to check out what they're offering. 01:09:56.880 --> 01:09:58.180 It really helps support the show. 01:09:59.120 --> 01:10:02.800 This episode is sponsored by Posit Connect from the makers of Shiny. 01:10:03.280 --> 01:10:07.260 Publish, share, and deploy all of your data projects that you're creating using Python. 01:10:07.860 --> 01:10:13.860 Streamlit, Dash, Shiny, Bokeh, FastAPI, Flask, Quarto, reports, dashboards, and APIs. 01:10:14.820 --> 01:10:16.340 Posit Connect supports all of them. 01:10:16.680 --> 01:10:22.000 Try Posit Connect for free by going to talkpython.fm/posit, B-O-S-I-T. 01:10:23.120 --> 01:10:25.160 And it's brought to you by Auth0. 01:10:25.840 --> 01:10:30.100 Auth0 is an easy-to-implement, adaptable authentication and authorization platform. 01:10:30.820 --> 01:10:37.320 Think easy user login, social sign-on, multi-factor authentication, and robust role-based access control. 01:10:37.720 --> 01:10:42.660 With over 30 SDKs and quick starts, Auth0 scales with your product at every stage. 01:10:43.260 --> 01:10:48.800 Get 25,000 monthly active users for free at talkpython.fm/auth0. 01:10:49.880 --> 01:10:50.760 Want to level up your Python? 01:10:51.200 --> 01:10:54.880 We have one of the largest catalogs of Python video courses over at Talk Python. 01:10:55.340 --> 01:11:00.020 Our content ranges from true beginners to deeply advanced topics like memory and async. 01:11:00.420 --> 01:11:02.560 And best of all, there's not a subscription in sight. 01:11:03.040 --> 01:11:05.580 Check it out for yourself at training.talkpython.fm. 01:11:05.980 --> 01:11:10.440 Be sure to subscribe to the show, open your favorite podcast app, and search for Python. 01:11:10.890 --> 01:11:11.780 We should be right at the top. 01:11:12.280 --> 01:11:21.140 You can also find the iTunes feed at /itunes, the Google Play feed at /play, and the direct RSS feed at /rss on talkpython.fm. 01:11:21.800 --> 01:11:24.040 We're live streaming most of our recordings these days. 01:11:24.390 --> 01:11:31.880 If you want to be part of the show and have your comments featured on the air, be sure to subscribe to our YouTube channel at talkpython.fm/youtube. 01:11:32.900 --> 01:11:34.020 This is your host, Michael Kennedy. 01:11:34.440 --> 01:11:35.280 Thanks so much for listening. 01:11:35.540 --> 01:11:36.420 I really appreciate it. 01:11:36.800 --> 01:11:38.380 Now get out there and write some Python code.