The Python Podcast.__init__

Share on social media:

[00:00:13] Unknown:

Hello, and welcome to Podcast Dot in It, the podcast about Python and the people who make it great.   When you're ready to launch your next app or want to try a project you hear about on the show, you'll need somewhere to deploy it. So take a look at our friends over at Linode.   With the launch of their managed Kubernetes platform, it's easy to get started with the next generation of deployment and scaling powered by the battle tested Linode platform,   including simple pricing, node balancers,   40 gigabit networking,   dedicated CPU and GPU instances, and worldwide data centers.  

Go to python podcast.com/linode,   that's l I n o d e, today and get a $100 credit to try out a Kubernetes cluster of your own. And don't forget to thank them for their continued support of this show.   Your host as usual is Tobias Macy. And today, I'm interviewing Jairo Yopis about Copier, a library for managing project templates. So Jairo, can you start by introducing yourself?  

[00:01:06] Unknown:

Hello, everybody. I'm Jairo Jopis.   I learned programming   like 10 to 13 years ago,   just because I needed   something   back there in where I was working. Started with Visual Basic, PHP, JavaScript, and then Python.   Right now I am full stack   developer,   at Technitiva since   2016, and also the security   infrastructure and developer tools   responsible.  

[00:01:36] Unknown:

And do you remember how you first got introduced to Python?  

[00:01:40] Unknown:

Not exactly. I think it must have been like 10 years ago or or something like that.   I landed by myself   just because I was   hitting   some maintainability problems in those PHP   projects I had, and I wanted something better.   And I dive into Python 3 dot net,   which is a nice website for learning Python. I liked it. I started   working with it, and   suddenly my other languages became more Pythonic, so I knew this was the language.   And, well, later,   I knew Odoo, which is   ERP or framework for ERP,   something like that,   where it has a lot of potential and started working on it. And right now, it's my main,   business,   my daily work.  



[00:02:33] Unknown:

And so somewhere along the line, you ended up getting involved with the Copier project. So can you start by just giving a bit of an overview about what that project is and how you got involved with it?  

[00:02:44] Unknown:

Copier is   this kind of tools are usually called template managers   or scaffolding manager or generator.   There's some tools similar.   However, since version 3,   which is the version I helped develop,   I would say it's more a project life cycle management tool,   which is somehow unique.   And I got involved,   because, well, I told you before I am working with Odoo, but Huddl has a very steep   learning curve.   To develop it, you need a lot of packages, not just   from Python, but from many things you cannot pip install, although   it's way more than that.  

And its customer needs,   specific flavor of Hadoop, so it's very difficult.   I had to develop   1 system, which is called Dutba.   It's highly opinionated   image ready to put Odoo inside it, but without Odoo.   So   it needs,   templates   to   configure   how do you want to build Odo for this project.   Well, I needed   some templates tool,   but when I started this project, I mean, Tudo was the image.   It had also Duda Basket Folding, which was the template.   This was   2017.   There were no   project life cycle management tools available.   There were   project template tools, but this was not enough for our case.  

So I just started with a git repo and merge, git merge and manual patch. And   fast forward to   2019,   git merge is just not enough.   All the template managers says are not enough, so   they all needed something better.   Copier was not enough. So   but it was the closest 1.   So by the end of 2019,   I started doing my first pull request to Copier, and then later I became a co maintainer.  

[00:04:56] Unknown:

The full life cycle management capabilities of Copier are definitely what I find interesting. And you mentioned that when you first came to it, it didn't quite have everything that you were looking for. So I'm wondering if you can give a bit of the background of   where the project came from and the state that it was in when you first found it and what you saw as the promise   to enable you to take it to where you needed it to be?  

[00:05:18] Unknown:

Well, I have to ask the other man trainer.   He is called Ben Feller, and   he is very nice.   And I have to ask give history to get some reserve to project because I'm new in it somehow.   This project was born in   2011   by Juan Pablo Scalletti,   who I never met. The project was called Voodoo   back then.   It seemed like it had a joke of resurrecting project skeletons.   Then in 2018,   we can see the first comment from Ben.   And last summer,   it was   Juan Pablo left the party and Ben Feller was the new maintainer. And then,   so do by the end of last year, I started contributing. And   in January, I became a command center.  

This contributing ID since late 2019   to   around   April 1st,   sponsored by Technitivo.   But these days, Ben is very busy, and I'm mostly maintaining   it on my own in my free time.   Basically the state of the project was a simple project.   I like that.   Risk following managers,   well,   these tools,   there are not many of them, at least not many serious   ones.   The other ones, all of them   had very complex   mindsets   or workflows   or ways to deal with the template itself.   So this was a little simple project.   You were able to make a template very easily,   and I like that. I like simple things.  

So I thought that if I had to invest a lot of time improving 1 tool, I wanted to improve a tool that was simple,   not something to be too complex   that was gonna be very hard to prove.   Back then, before I started, contributing these new features,   the thing I liked most about Copier was how simple it was.   I saw the the the source code of the project was simple, but also   the template   you produced   with it   were simple also.  

[00:07:35] Unknown:

In terms of the actual   uses for copier   and other project templating tools, I know that there are a number of different ways that people have employed them. You mentioned the need for   being able to set up an Odoo environment and all the different packages and configuration necessary to go along with that.   There are projects for being able to set out the skeleton of a Python repository.   Ruby on Rails has its own built in scaffolding engine to bootstrap a project. Django has 1. I'm wondering if you can just talk through some of the   common use cases that you've seen and that you've used these templating tools for, and then maybe talk a bit about how Copier compares to the overall ecosystem of the available options.  



[00:08:21] Unknown:

We are programmers,   and we love   to, to keep our code dry. What we call dry, don't repeat yourself.   That's very nice, but sometimes you just cannot   do that.   Recently, I started 1 very, very little library that I needed for specific need. It's called Versort.   It's for sorting versions.   It's very small. It was like an exercise   to see how much   these   undryable things   are in a project. This project is 144   lines of Python code,   plus   111   lines of Pytest code. So it's very, very small,   but the total amount of lines   it's   678,   almost 700 lines   for   around 150   lines of real code.  

Where are those lines from?   It's dot GitHub slash worksflows   slash,   I don't know what the yaml.   It's the license. It's precomicconfid.jamal.   It's Travis CI or GitLab CI or pritzhererc.jammerorreadthedocs.jammerormypy.inioypides.iniomkdocs.   That's yml. Editorconfinflak8.   Configuration   for Versus   Code. Well,   every new IDE,   every new automation   tool that comes to the market   says the same to you. Hey. You just have to add 1 dot 5 to your project.   But finally, you end up with a 1, 000 of dot files,   and you really need them because those are great tools   that save time for you. But how do you manage all those configurations for your projects?  

Well, this is a very specific aspect where you happen to need a tool   that handles all of these   repetitive things for you. So when you cannot keep your code dry, you need a drying machine and this is copier.   You also asked about how does it compare   with other tools? I will say that there are 2 major alternatives to Copier, at least otherwise the analysis I made before   investing time on developing   it. 1 of them   is cookiecutter,   which is also written in Python, very famous in the Python world.   And the other 1 is Yeoman.   Both of them are   very good at what they   do, but these are just templating tools.  

They only serve to bootstrap a project and many others you also mentioned because I also   looked at many other   alternatives, although these 2 are the biggest ones. All of them have the same problem. All you do is bootstrap the project.   So, okay, I bootstrap my project. I create these, let's say, pre commit config dot yml file.   Okay. But then   after some time, that configuration   also evolves.   Maybe   some CI tool requires   new   syntax,   maybe   some tool you are using with Precommit   gets a new release with a bug fix you need and all of that. So you need to manage all of that.   I'm talking just about this use case, but any other use case also   requires   maintenance.  

Well, this is what I call day 2 operations.   It's cool to start a project. Yeah.   Everybody can do that. You can even just copy a folder you have.   But   what happens the next day, and the next week, and the next year? And what happens if you require that your framework   has a specific   folder structure,   and you want to provide a template to your community, which was our case, we used to do the project.   This template needs to evolve with the project.   So what do you do? How can you help people evolve their projects?   This is a key feature of Copier,   that as far as I know, no other templating tool has.  

And Copier   relies on Git   and uses, SmartDiff   algorithm   that compares   the template evolution, the template git evolution,   with   your project evolution.   And then somehow tries to apply diff   just like git would do   if you   have   both stories in your git project, which is not the case.   You just have to separate completely different stories because,   yes, you you you use the bootstrapping,   but then your project evolves   as it want it wants. You can even change some answers to some questions.   And then this SmartDiff algorithm   that I developed,   handles all of this   and lets you actually evolve your projects.  

This is, I think, the best feature of Copier, but it has another 1 that also I didn't find   in any of the other tools,   which is the ability to apply several   templates   to a same project.   So let's say that you develop   several languages.   For instance, you develop,   let's say, JavaScript projects   and Python projects.   If you develop   JavaScript stuff, you're gonna need the NPM   configurations,   JavaScript configurations. I'm not a JavaScript developer, so I might be failing   in something   I say.   Well, you need your kind of tools. See, if you develop Rust, it's the cargo stuff.   And if you develop Python, you might need to set up the py or you might prefer a pyproject.  

Yml or a PPM, whatever.   So you have separate   scenarios   depending on the language you're using,   but   many of them   use the same tools.   Let's say you use all of these to produce   Docker images.   Okay. Then the Dockerfile is is common for everyone, or maybe the Docker ignore a file,   or maybe the   GitHub workflows,   things like pre commit config   that make your code pretty no matter what kind of code are you writing.   So   there's a split of needs. You may need to apply the predefined tools,   but   also the Python specific tools in a project.   And in a different project, you need to apply the predefined tools and the CI   specific   files also, or maybe the JavaScript ones.  

So Copier lets you   apply several templates to our same project,   and this combines with a previous point. So both templates   can be applied simultaneously to the same project and make that project evolve   also.   So these are 2 killer features. I think Copier is,   you might like more   something   of the other projects, but these 2 features are essential   distinguishing.   And there are a couple more points.   1 of them is that you don't have to write JSON, which I think it's a big feature   as compared with the other tools.   I hate writing JSON. Don't know what do you think, but I hate   it. You you write Yamo on the other hand in case you like it.  

The other feature is that for publishing a template,   there are some   tools   such as Yeoman   or also I think it was something like mister Bob templates for Python,   where you need to produce   an actual package   to make a template.   Because for instance, Yeoman is not a template manager, it's more a template framework,   which helps you build a note project,   which is your template.   But   if I'm developing Python   and I'm a Python developer,   and I don't know how to do a a NPM project, or I don't like JavaScript.   Why do I have to learn JavaScript,   to learn NPM, to publish my templates   as an NPM package   just to help people   deal with Python stuff. It makes no sense.  

But on the other hand,   I like Python. I know how pip works, but also maybe somebody comes from Node and wants to use Copier and they're in the opposite situation.   So Copier,   if you want to publish a template,   you can just use a git repo,   and it's just enough.   I have a blog post in my blog where I explain in the in-depth   why Copier think it's way better than our alternatives.  

[00:17:48] Unknown:

The specific thing that intrigued me about Copier and maybe wanna reach out and learn more about it is the ability for being able to apply changes to the underlying template to projects that were generated with it, which   most tools such as cookiecutter or Yeoman, as you said, you can generate a baseline scaffold.   But then as you work on other projects that use some of that same structure, you find improvements or enhancements, and then you bring that back into   the project template that you're working with. But there's no way to then reflect that back out to all the other projects that it was created with. And so you have to try and figure out doing it manually in a piecemeal fashion.   And so you end up with a lot of drift in terms of the best practices that you've applied. And so your original project doesn't get to benefit from the learnings that you found in project number 5 or whatever. And 1 of the things that I didn't realize in what you were just saying is the ability to combine multiple templates.  

You can actually   rather than having to have 1 monolithic template that covers all the concerns that you need for a project or have   a bunch of different conditionals that it will generate project skeletons for based on the inputs that you provide.   The input prompts, you can instead have a modular approach where you have a template that says, this is going to handle all of my   tooling for my configuration. So it will put in my pyproject.toml.   It'll configure, flakate. It'll set up my py. And then this other 1 will set up the baseline for the Django app structure. And then this other thing will handle setting up all the configuration for my CICD, and then I can apply all those together,   or only 1 or 2 of them, rather than having to have everything in 1 project. I think that's a pretty amazing capability as well.  



[00:19:32] Unknown:

I think these are very   important features for the project.   I mean,   the ones that make you choose Copier over other projects.   It has others. For instance, even if even your templates can share   code among themselves. So you maybe have a question, Adi.   When I say questionnaire, I mean, you ask questions to the user so you can produce the sub project you want. Okay?   So if you have a questionnaire,   you can actually combine   several questionnaires in 1.   So if you have several templates,   you can include them   just skids modules and combine   in the main template   several parts.  

This is something that is not perfect yet, but   it also helps. So it's very good, I just say.  

[00:20:26] Unknown:

And so digging more into the project itself, I'm wondering if you can talk through the actual   copier project and how it's implemented   and how the overall design and feature set has evolved over the past year that you've been working on it.  

[00:20:41] Unknown:

When I since I've been working in it, I think these 2 key features   I told you were new in version 3. When I came to Copier, it was versions   2   dot   something. So   it's these new features is something that I am involved with, so I'm happy with it.   But the project itself, the settlement   of the project as it was when I came in   and how it is now.   It is,   API   and CLI   project.   So main use for copier is CLI.   You use it in your terminal.   It should be comfortable   there.   But you can actually use it as a library if you need to expand anything.   It's written for Python   3.6   or later.  

Recently, it supports 3.9 also in the latest version.   It uses,   poetry to manage the project, which is a pleasure. I love poetry.   And   also   it's completely   typed.   Well, with static typing, it uses my pie to check that.   If you plan to use Copier as an API tool, as a library,   let me tell you that please use just the copy   function in the main   module because   everything else is gonna change. We'll talk about that later.   So just   use copy, which is the makes most of the work.   Something that is very, very nice about copier   is   how it has a very big test suite   that helps us develop safely.  

And I think that the most interesting part is how do you actually   make a template?   Because   most people, I think, don't really   care about how is the tool written, but they care more about how do I write my templates,   which is what affects them more   directly. Right?   So   you don't need to add any logic to your templates. You can just use copier   to copy a folder.   But if you need to add logic, you have Jinja too. You don't need to add any configuration to your templates.   But if you need it to just add a copy of the the demo   file, which also   can   can evolve from simple to complex to multiple   includes   easily. So   it's   as complex as you need.  

You don't need your template to be a git repo, although   if you use it, it's better, and you have   other features such as updates.   You don't need to support updates in your project. So it's something that the template   explicitly supports.   And if you don't support updates, then CopyEdge has becomes scaffolding tool, just like the   other tools we also talked about.   But if you need those updates,   all you need is to   allow your template to write, copy your answers file, which tracks last answers from the project.   You need to   make it git repo, and Copier will use Git tags to evolve your project.  

You also don't need to program   anything,   but if you need to program something for your template,   Copier uses super processes   where needed.   So if you're a template's   writer,   you don't need to know Python.   You can just use any binary you want. Copier will communicate with the binary for some tasks   just using the arguments you say to hit to tweet   and some environment variables. So it's very easy to block with   any tooling you want.   And I said it before also, you don't need to publish a package. If you want to publish a template, you can just publish a git repo, and you're done.  

[00:24:50] Unknown:

To your point of being able to call out to any arbitrary   command as part of the template generation   plays into the fact of it being language agnostic. And you called out earlier the issue of   if you like Yeoman, for instance, but you're not a JavaScript developer, you still have to work with the NPM tool chain and things like that. I'm I'm wondering if you've looked at any   tooling around Copier to be able to package it up as a single executable so that somebody   who's interested in using its capabilities but isn't a Python native can still be able to benefit from it, and if you have any of the challenges or issues that you've come across in that process.  

[00:25:32] Unknown:

Yes. Actually, that's the main reason why this is done like that. Well,   that's 1 reason. The other 1 is that the project have this feature already when I came.   So I like that. And since I had been   checking Yeoman, I just had, for example,   I compared that and I said, okay. I like this. I like that Copier is a templating tool for the world, not just for the Python world. It's much better.   So if I write Rust   and I want to let   my template users   just execute   tasks against the template   with a Rust library,   or if it is written in Go, or if it's JavaScript or whatever.   I don't want these people to care about   anything else than just pip install   well, better, pipx install copier.  

And that's it. If they do that, they   know just copier docs. I mean, there's something they will have to know, which is Jinja.   But I think it's a very simple templating language, very comfortable. So that's   well, at the end, you have to to have some template language.   But apart from that, you don't need to write a single Python line to make your project your template   be able to use all Copier features.  

[00:26:56] Unknown:

And so digging a bit more into the process of building templates for Copier,   I'm curious if you have gone down the path of taking an existing template for something such as cookie cutter and converting it into something that is compatible with Copier or any of the other frameworks. And what are some of the design considerations   for template authors to be able to build something that will work well with Copier and all of its capabilities?  

[00:27:23] Unknown:

My use case   was a very complex 1.   I mean, my use case was   so complex that I could not use   cookiecutter   or human.   So   1 good thing about how Copier has developed   is that I used it. I mean, I don't work gain   too much money with Copier. I just   work with other things and I needed something that   did this work. So   if you take a look at a repo that is called Dutba copier template,   you can see it's a very, very complex template   and it helps to make copy of what it is. But   after   Copier 3 was released,   some people started liking it, started using it and started migrating cookie cutter templates to copier templates.   And I think this is   bit of a challenge because   copier is a new mindset.  

You cannot have a template which is compatible with both.   You can have a template which is similar,   but it's not compatible,   a 100%.   So you might have to read carefully the documentation to make your templates   match copiers.   1 differentiation   is, for instance, in copier, you don't need that your template is a subfolder   of your project.   The project   and the template can be the same folder.   In Qutr, for instance,   you have a main folder,   which contains your readme, your license, your whatever, and then a folder inside that repo   that contains the actual template.  

But in Copier, it doesn't   necessarily work like that.   Actually, it didn't support that, but later we added support because somebody   was asking for it because he came from cookie cutter.   But you don't actually need that because in copier,   for a file to be considered a template, a Jinja template,   is masked and in a specific suffix,   which by default is dot   t m p l.   So let's say your project contains   readme.md   and then a readme.md.tmpl.   Copier will ignore the first 1 and just take the second 1.   So if you want to have a readme for your template,   but also a different readme   generated from your template,   you can just have these 2 files together,   then you don't actually need to have your template inside a subfolder.  

So it's just a matter of taste. How do you prefer to organize your your things?   But it's a mindset change that if you come from cookie cutter, you you need to do. Last week, I think it was, we had an issue.   Somebody was asking us to support having several templates   in the Sangit repo,   but this is not possible for us   because Copier uses Git tags   to evolve your project.   So if we were to do that, you would have several templates,   which will   evolve   separately,   but actually   all would be versioned with the same version.   You would have   some confusing   things. Things like,   template evolving,   having a new release, but with no change.  

And so   1 Git repo   will be 1 template,   and this is by design.   So we'll be like that forever, just because   we need to support updates. And and because we designed the project with a specific   goal,   it requires a specific template.  

[00:31:16] Unknown:

In terms of people who are using Copier, what are the options for extensibility   or integration with it? And   particularly, you mentioned the Python API,   just some of the interesting capabilities or features that that exposes.  

[00:31:32] Unknown:

I think it's a matter of of comfort   because   let's say,   for instance,   I use   1 CI,   internal CI,   which applies   to our company projects,   the public template we have,   plus another   private template that we also have for this kind of projects. This is 1 example of how multiple templates per project help   because, for instance, the public templates   will help everybody to get up and running with   quite easy. But the private 1,   makes our specific   customizations,   our internal   CICD system work,   and other would for nobody else. So it's a thing we maintain   internally,   and every project has both of them. So 1 CI system   just   every night checks for a new release   in both templates.  

And if there's a new release,   then it updates the project.   It runs the checks.   And   if there is any conflict or any problem, it will   just open a pull request.   But if there's no problem, it will also merge the pull request. And so the next morning you sit   in your desk   and your project is updated because you made a release   from the template.   So   if you just use command line based CI,   I think you will be more comfortable using   Copier CLI   or for your daily usage of Copier, it will be more comfortable also. But if you have a specific   CI tooling that you happen to have written in Python,   I think you will be more comfortable using Copier as a library.  

But actually you can make the same thing with both approaches.  

[00:33:32] Unknown:

And in terms of the actual   uses for Copier, what are some of the most interesting or innovative or unexpected projects that you've seen built with it? Well, to be honest, I have not seen many  

[00:33:43] Unknown:

because   I don't track copier users.   We have in our readme 1 suggestion.   Please type your copier templates   as copier template.   There's a topic in GitHub   labeled copier template.   So we just expect people to tag their templates,   and then   every now and then   come around and see what they're doing.   I think the more the most interesting thing I have seen there   is there's 1   contributor we have, very active, actually. It's called he is called. Sorry.   He's called   hang on. I'll try to say it. Okay. Timothy Matsukotelli,   and he is the main tenant of MK Doc Strings. So it was a surprise for me to see   him involved in this project that he seems to love Copilot very much. And he has a template   to build poetry based Python projects.  

Myself,   I started developing a template, which is actually, it's just a proof of concept.   It's under the copierarch   organization   in GitHub. You can see it. It's called Auto Pretty.   And my goal is to just bundle   all those kind of tools   do you usually need for any kind of project.   So I'm talking about linters,   formatters,   PreCommit,   Prettier, all these kind of tools that are very basic.   I happen to have everywhere.   And it's also a project that is trying   a new concept of a self   templating template.   So I want to be able to have a template   to prettify things,   but to actually be able   to apply these templates to the template itself.  

So I can update my dot files for the template   from the very same template.   Well, it's not released yet. It's just there are some alpha, you can try it. And it's not working yet, but it is like a playground I have. And at some point, I will make a better release.  

[00:35:53] Unknown:

And in terms of your experience of working on and with Copier and using it for your own projects, what are some of the most interesting   challenging lessons that you've learned in the process?  

[00:36:04] Unknown:

I think I learned a lot of things.   To start, I learned,   lots of tools that I didn't know.   I might seem   a little bit stupid saying this in a pocket, but I never wrote Pytest test, and it's awesome. I   like it.   I started using Poetry. I liked very much. Also, this is the first project where I am deeply involved   that has static typing,   and it's very good. It helps a lot. So   that's something I learned.   Something I also learned is that sometimes you need   to test the template.   At first,   since I was the only 1 developing my template and using it,   nobody else   would use it.  

Well, I just   started releasing versions and versions of the template without any problem when anything went wrong.   But later, when this template became a more critical part   of our toolkit   in the workplace,   and all my colleagues   started using it, and the CI system started updating projects   automatically.   Then something I learned is that   if you happen to have this kind of usage also,   which is cool because it's where copier shines actually,   I recommend   to make pre releases of your template   and apply them manually to some specific projects, or maybe if you are several   developers   involved specific template,   Do developers,   little group of people,   try your premises   because it will help. Sometimes   it's hard to predict   how a project will evolve   and how your template will behave.  

Because,   well, this SmartDiff algorithm   makes   most of the work for you. But sometimes,   you will try let's say, you add a new file to your template,   and you didn't happen to   expect that that file was existing before   because the user   added it manually to a project   or maybe changed   somehow.   So by having some prereleases,   you can there there's a flag in Copier CLI,   which   is slash slash   pre prerelease   that tells Copier to consider pre releases when when fetching the last the the latest version of the template.   It helps you to test your template before it's released.   Apart from that,   app tests   app tests. You don't usually need to add a test that tests that the template   when the template has a file that is called   whatever and it has a content and you pass that   answer,   copier will render that content. Well, that's obvious.  

But   so don't test what copier is doing.   Test why is it doing it. So in your tests,   create a new project. And let's say that your test is testing   that you install PreCallmate   configuration, which includes black. Okay.   Actually, I want to test that. Then in your tests, create   a new template, a new sub project from that template,   and then add a Python file, which is badly formatted.   Try to commit that   and see how pre commit performance   that. So you're seeing   the way   you the way you do things and not the how you do things. And it's important for testing, for your test to be because if it just says that the temp file renders   like this when I pass   these kind of input,   well, it's gonna be true all the time,   but maybe if the input is wrong or the file is wrong, you won't detect that.  



[00:40:02] Unknown:

For people who have existing projects that they want   to extract some of the structure and best practices from and apply it to other systems, is there any capability for   being able to use copier on a project that already exists to apply some of the boiler plate and overall structural best practices to the project?  

[00:40:23] Unknown:

Yeah. Copier takes a simple approach   when analyzing your project.   And it has actually 2 commands.   The first command is copy and the second 1 is update. So   when you're   calling copy, it will   just copy everything and forget about what those files contained before.   So let's say your project is already a Git project.   Well, you just   apply the new template, copier, copy, whatever,   and then copier will   do his stuff,   and then you will have to review   the files that copier modified.   Why would you do that if the template supports updates? Because,   like I said before,   it's not mandatory.  

It's a template   choice.   If it supports updates,   it will write a file that by default is called   dotcopieranswers.yml,   but you can change that.   Actually, you have to change that if you want to apply several templates. That's how it works.   Let's say you just use 1 template. That's the name of the file. Then it will store   all your answers to the questionnaire,   plus   the URL   of your git repo,   plus the tag that you applied.   So   copier,   once you commit all those changes,   copier will consider   that   the resulting   of copying that template   in that version   with those answers   is your sub project right now.  

So it will   later   apply an update.   This algorithm   will compare   how it should have been   and how it comes to be, and then later evolve. But if you just have several projects   and want to apply Copier over them,   Once they already exist,   it's completely support. All you have to do is just copier copy   the first time,   and then   later, just copier updates, as usual.   That first time, you will have to review not only what copier is doing, but there's no other choice.  

[00:42:40] Unknown:

And for people who are looking for a project templating tool or something to help manage the overall life cycle of their projects, What are the cases where a copier is the wrong choice?  

[00:42:51] Unknown:

I hope it's the good choice.   That's why I like it. But when it is the bad choice?   I said that we try to dry things   to don't repeat   yourself in your code. And   when you cannot   dry, then you have a drying machine. Okay. But if you can dry,   just dry your code. You don't use copier.   Better dry it. If some parts of your codes can be externalized in a library, then do that library. Don't just copy that everywhere.   And I actually do that   because it's faster and more and easier. But I have plans to me, right, to actually extend the library for this,   copier template project I have.  

So I'm telling you not to do that, but it works.   So so maybe it's also not a bad choice.  

[00:43:44] Unknown:

As you continue working on Copier and continue using it, what do you have planned for the near to medium future of the project?  

[00:43:51] Unknown:

Copier 6 is gonna be a huge release.   Really, really huge. Until now,   let's say copier 12 was,   simple, fun   scaffolding project, just like any other, but easier.   Copy of 345   has been   the best templating engine in the world.   No. Not the best, but, you know, it has these killer features.   But Copier 6 is gonna be a complete refactor of Copier.   I am confident about it because we have very, very big   test   coverage.   So I'm refactoring it because Copier was built around   functions,   but functions were too dependent   among themselves. And at the end of the day, it became   hard to   detect   when is something happening, when not, or to have a relationships   among the whole   copying process.  

So   it became hard to maintain in that regard, and I'm making a bigger factor to do it object oriented,   which is gonna be way easier to maintain in the future.   Right now, there are some alpha releases of Copra 6, but are very, very far from what Copier 6 is gonna   be. But if you use them, you will help me because it will detect bugs. So   do it, please.   And you will have   conditional questions. That's something that it's already in the last ask for.   Also, a more interactive   terminal user   interface,   which for instance, also supports multiline input.   That was not easy, but   it's working now. It has some bugs, but, well, it's   more things   that are gonna come in Copier 6 are   multiple answers for the same question.  

That's something asked asked by the community,   And, also,   the self templating   support   to have a template that applies to itself, like I said before.   And I will take a chance to remove some options that   make no more sense that,   those kind of things you add,   but don't really have much sense. And 1 thing I would like to do also is to change Jinja defaults   because right now, Jinja is,   by default,   different of the official Jinja. For instance, it uses   brackets   instead of curly braces.   So I think that if there's somebody who comes to Copier for the first time,   and then he has to go to the Jinja website and for the first time   learn Jinja.  

And maybe somebody who doesn't even   write Python.   Well, it can be challenging if apart from all of that,   also   Copier uses different placeholders   than official Jinja.   So possibly there's gonna be some changes there. Then maybe Jira templates will not work with Copier 6 if they worked with Copier 5. So another things that I will have to add is a version tech   that fails if your template is not ready for   Copier 6. I have to think about that a little bit more.   But right now, I am mostly involved in the refactor.   And once the refactor is settled,   then I will start adding these other things, which are gonna be very much easier   after the source code is reorganized.  

And after copy of 6, then I think   there's gonna be not   some main more things to do. The project is very, very nice.   Just more   evolving of the tool, but it's gonna be more more or less what it should be.  

[00:47:54] Unknown:

Are there any other aspects of the copier project or the overall topic of project templating and scaffolding and life cycle management   that we didn't cover yet that you'd like to discuss before we close out the show?  

[00:48:07] Unknown:

There is 1 complex   case   in Copier,   which is answer migration.   It happened to me in my template   when I released, I think it was version 2.   You can answer to copier   in YAML format.   So an answer to a copier question can be anything   that YAML or JSON supports.   So you can   put a dict, an array,   a boolean, or whatever,   combination of them as an answer.   So let's say that you expect a specific format,   and then later   it needs to change.   It happened to me because the format I was asking   was not smart enough   for, different well, actually, if you want to include it,   it was because of traffic, which is an amazing inverse proxy,   which   for traffic   1   was   much simpler   to use and to set up. But for traffic 2, it's much more complex,   but actually also very much more powerful.  

So the structure   we needed in our project to include the traffic configurations   was different because we started supporting traffic too. And then,   for instance, things like   supporting several   host names for a project   was not possible before. Now it was possible   that structure didn't match. So   Copier includes a migrations   feature   that   allows you to even   change   the answers   before migrating.   And this is very handy because   if you had your project in template version   1,   and then for template version 2, some question needs to change its structure.   You can automate that.  

And then your   copier project, when updating to version 2, it's gonna take the answers from version 1. It's gonna convert them to the new format,   and then   use them for your version 2 template. Well, it's not copier who's gonna make it. It's you because you are the 1 who defined that structure.   But you have to program that in your template,   And that's,   a bit of a pain points, so   I advise to   to try to keep your questions   simple if you can.   For instance,   if you want   to ask the user, what systems do you want to use? Please input   a YAML list.  

Maybe it's simpler for you to just say   2 booleans.   Do you want to use system a? Yes. No. Do you want to use system b? Yes. No.   So it's easier to evolve that kind of questions,   but it's not always possible. So commits across migrations also.   And another thing that I recommend   is that, well, when copier   updates   automatically   a project,   it can detect conflicts just like a git merge.   But copier will leave a dot reg file,   which includes the conflicts.   So if you trust Copier too much,   maybe   you can   say,   okay. Copy of that worked. Then the project is okay. But if there's a reg file,   possibly it's not okay. That's something you have to review by yourself. That's something that the Smart diff algorithm   was not able to solve.  

So there's Precommit   hook,   which I think it's in the docs   copier,   as a recommendation to forbid your   git project to commit that reg files. Because   that way you make sure you are not committing   a failed   update. It's important.   And also a little problem that many users face   is that they expect Copier to work   a way that it doesn't work. I mean,   when these users update project,   they copy your   answers file. And then after it's been edited,   they commit that   and then they run copier update force, copier force update. Sorry. Then they're tricking copier. They're telling copier that   those answers   produce that project, but it wasn't true. The answer that's produced that project were the previous ones. So maybe copier   will succeed,   could happen,   but possibly it will fail also because you're tweaking this SmartBeef algorithm. So if you need to change,   an answer,   use   copier to do it. Do not edit copier answers directly.  

This is not documented in the stable documentation. It's documented in the latest branch of the documentation.   So maybe you will not find this advice   yet, but just don't do it.   Just say you can pass the new answer to copier by the data flag in the CLI,   or you can just   answer the questionnaire again. The the last answer is really there, so you just have to change the 1 that changed.   But don't do it like that because   it will fail at some point and you will think   that it's a bug and it's not.   So   just let's copy or edit that file.  

[00:53:41] Unknown:

Well, for anybody who wants to get in touch with you and follow along with the work that you're doing or contribute to the work that you're doing in copier, I'll have you add your preferred contact information to the show notes.   And so with that, I'll move us into the picks. And this week, I'm going to choose having a good quality set of playing cards on hand because   it's a versatile   tool. You can use it for playing all kinds of different games, either by yourself or with other people. So definitely worth having 1 that is   good quality and can stand up to a lot of use rather than just something that's cheap because then they're not as fun to use and you're less likely to pick them up. So definitely recommend just having some good playing cards around. And so with that, I'll pass it to you, Jairo. Do you have any picks this week?  



[00:54:21] Unknown:

Well, I have some.   1 thing I tried recently was Mozilla Hubs. I don't know if you have tried it,   but it's very nice.   Mozilla Hubs   is an alternative to a video call. It's not a game. It seems like a game, but it's not a game. It's a video conferencing tool in virtual reality,   which helps   you stay in a three-dimensional   area   where you can hang out with your friends or workmates.   And it's very fun   because   it avoids   the Zoom burnout,   the video conference   burnout that your brain experiences. It's something   interesting also   could be an epic.  

These days,   most people need to   stay away from their friends,   but using this tool, you can feel like you are in the same room. And   1 thing that seems stupid is like copier, has little features that make your life different.   And this little feature of,   hey, I'm with 10 friends, but I want to talk to 2 of them, then we can go to a corner of the room and talk. And   you don't have this   chicken house   noise   when everybody is speaking in the same video call. It's very nice.  

[00:55:48] Unknown:

Alright. Well, thank you very much for taking the time today to join me and discuss the work that you've been doing with Copier. It's definitely a very interesting project and a   well designed tool for being able to help manage the full life cycle of projects and the boilerplate occur that spans across multiple different projects. So thank you for all the time and effort you've put into that, and I hope you have a good rest of your day.  

[00:56:09] Unknown:

I just want to say thank you to Juan Pablo Escaletti for starting the project, to Ben Felder   for maintaining it during last year and also   this year and making me a comment in it just because he liked my work. So thank you.   Also, thank you to Technitiva   that has sponsored   the work   of copier   from version 3 to version   5.   But latest version, latest stable version   because   they just needed a good tool that didn't exist, and they decided to let me invest time on it.   Although from now on, it's   just   basic issue management, but I have to develop that in my free time right now. And also   thank you to Timo Seema and Mazzuccotelli   because he helps a lot, and he provided for us the basic skeleton for building   our documentation,   which looks really cool and it's all thanks to him. So thank you.  



[00:57:15] Unknown:

Thank you for listening. Don't forget to check out our other show, the Data Engineering Podcast at dataengineeringpodcast.com   for the latest on modern data management.   And visit the site at pythonpodcast.com   to subscribe to the show, sign up for the mailing list, and read the show   notes. And if you've learned something or tried out a project from the show, then tell us about it. Email host at podcastinit.com   with your story.   To help other people find the show, please leave a review on Itunes and tell your friends and coworkers.