Drafts

With the latest version of minecraft it requires a very new, possibly the latest, version of java. Lately we have been getting into modded minecraft and I maintain the server for us. It’s been tricky to say the least. One hurdle I recently hit involves having the wrong version of java. I was getting this error trying to get a 1.12.2 forge server running. Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader ‘bootstrap’) In researching our errors, I found this on a forum. Pre-1.13 Forge only works with Java 8. I don’t write java, or really know how to manage different versions of java, but I have nixpkgs installed and it has a ton of odd stuff like this readily available, so searching nixpkgs [1] landed me with this. nix-env -iA nixpkgs.jdk8 once I had this installed I then just changed out java for the full path to my new nixpkgs.jdk8 java and it worked. /home/walkers/.nix-profile/bin/java -server -Xms${MIN_RAM} -Xmx${MAX_RAM} ${JAVA_PARAMETERS} -jar ${SERVER_JAR} nogui I don...

I have added a hotkey to my copier template setup to quickly access all my templates at any time from tmux. At any point I can hit <c-b><c-b>, thats holding control and hitting bb, and I will get a popup list of all of my templates directory names. Its an fzf list, which means that I can fuzzy search through it for the template I want, or arrow key to the one I want if I am feeling insane. I even setup it up so that the preview is a list of the files that come with the template in tree view. bind-key c-b popup -E -w 80% -d '#{pane_current_path}' "\ pipx run copier copy ~/.copier-templates/`ls ~/.copier-templates |\ fzf --header $(pwd) --preview='tree ~/.copier-templates/{} |\ lolcat'` . \ " I’ve had this on my systems for a few weeks now and I am constantly using it for my tils [1], blogs [2], and my .envrc file that goes into all of my projects to make sure that I have a virtual environment [3] installed and running any time I open it. [4] References: [1]: https://waylonwalker.com/til/ [2]: https://waylonwalker.com/archive/ [3]: /virtual-environment/ [4]: https://images.waylonwalker.com/copier-templates-tmux-popup.png

I often pop into my blog from neovim with the intent to look at just a single series of posts, til, gratitude, or just see todays posts. Markata [1] has a great way of mapping over posts and returning their path that is designe exactly for this use case. [2] To tie these into a Telescope picker you add the command as the find_command, and comma separate the words of the command, with no spaces. I did also --sort,date,--reverse in there so that the newest posts are closest to the cursor. nnoremap geit <cmd>Telescope find_files find_command=markata,list,--map,path,--filter,date==today<cr> nnoremap geil <cmd>Telescope find_files find_command=markata,list,--map,path,--filter,templateKey=='til',--sort,date,--reverse<cr> nnoremap geig <cmd>Telescope find_files find_command=markata,list,--map,path,--filter,templateKey=='gratitude',--sort,date,--reverse<cr> NOTE telescope treates each word as a string, do not wrap an extra layer of quotes around your words, it gets messy. [3] References: [1]: https://markata.dev/ [2]: https://images.waylonwalker.com/markta-list-todays-posts.png [3]: https://images.waylonwalker.com/markata-list-telescope-picker.png

Copier allows you to run post render tasks, just like cookiecutter. These are defined as a list of tasks in your copier.yml. They are simply shell commands to run. The example I have below runs an update-gratitude bash script after the copier template has been rendered. # copier.yml num: 128 _answers_file: .gratitude-copier-answers.yml _tasks: - "update-gratitude" I have put the script in ~/.local/bin so that I know it’s always on my $PATH. It will reach back into the copier.yml and update the default number. #!/bin/bash # ~/.local/bin/update-gratitude current=`awk '{print $2}' ~/.copier-templates/gratitude/copier.yml | head -n 1` new=`expr $current + 1` echo $current echo $new sed -i "s/$current/$new/g" ~/.copier-templates/gratitude/copier.yml

I’ve referenced a video from Anthony Sotile in passing conversation several times. Walking through his gradual typing process has really helped me understand typing better, and has helped me make some projects better over time rather than getting slammed with typing errors. https://youtu.be/Rk-Y71P_9KE Step 1 Run Mypy as is, don’t get fancy yet. This will not reach into any functions unless they are alreay explicitly typed. It will not enforce you to type them either. pip install mypy mypy . # or your specific project to avoid .venvs mypy src # or a single file mypy my-script.py Step 2 # [1] Next we will add check-untyped-defs, this will start checking inside functions that are not typed. To add this to your config create a setup.cfg with the following. [mypy] check_untyped_defs = True Step 3 # [2] The final stage to this series is to add disallow_untyped_defs. This will start requiring all of your functions to be type hinted. This one is probably the toughest, because as you type functions mypy can uncover more issues for you to fix. Often times the list of errors grows before it shrinks. [mypy] check_untyped_defs = True disallow_untyped_defs = True Anthony’s video # [3...

In order to make an auto title plugin for markata I needed to come up with a way to reverse the slug of a post to create a title for one that does not explicitly have a title. slugs a slug is generally all lowercase and free of spaces, and is a way to make website routes (urls) Here I have a path available that gives me the articles path, ex. python-reverse-sluggify.md. An easy way to get rid of the file extension, is to pass it into pathlib.Path and ask for the stem, which returns python-reverse-sluggify. Then from There I chose to replace - and _ with a space. article["title"] = ( Path(article["path"]).stem.replace("-", " ").replace("_", " ").title() ) To turn this into a markata plugin I put it into a pre_render hook. from pathlib import Path from markata.hookspec import hook_impl, register_attr @hook_impl @register_attr("articles") def pre_render(markata) -> None: for article in markata.filter('title==""'): article["title"] = ( Path(article["path"]).stem.replace("-", " ").replace("_", " ").title() )

I really appreciate that in linux anything can be scripted, including setting the wallpaper. So everytime I disconnect a monitor I can just rerun my script and fix my wallpaper without digging deep into the ui and fussing through a bunch of settings. feh --bg-scale ~/.config/awesome/wallpaper/my_wallpaper.png I set my default wallpaper with feh using the command above. Leaning in on feh, we can use fzf to pick a wallpaper from a directory full of wallpapers with very few keystrokes. alias wallpaper='ls ~/.config/awesome/wallpaper | fzf --preview="feh --bg-scale ~/.config/awesome/wallpaper/{}" | xargs -I {} feh --bg-scale ~/.config/awesome/wallpaper/{}' I have mine alias’d to wallpaper so that I can quickly run it from my terminal.

Getting docstrings from python’s ast is far simpler and more reliable than any method of regex or brute force searching. It’s also much less intimidating than I originally thought. Parsing # [1] First you need to load in some python code as a string, and parse it with ast.parse. This gives you a tree like object, like an html [2] dom. py_file = Path("plugins/auto_publish.py") raw_tree = py_file.read_text() tree = ast.parse(raw_tree) Getting the Docstring # [3] You can then use ast.get_docstring to get the docstring of the node you are currently looking at. In the case of freshly loading in a file, this will be the module level doctring that is at the very top of a file. module_docstring = ast.get_docstring(tree) Walking for all functions # [4] To get all of the functions docstrings we can use ast.walk to look for nodes that are an instance of ast.FunctionDef, then run get_docstring on those nodes. functions = [f for f in ast.walk(tree) if isinstance(f, ast.FunctionDef)] function_docs = [ast.get_docstring(f) for f in functions] ast.walk docs: Recursively yield all descendant nodes in the tree starting at node (including node itself), in no specified order. This is useful ...

Many tools such as ripgrep respect the .gitignore file in the directory it’s searching in. This helps make it incredibly faster and generally more intuitive for the user as it just searches files that are part of thier project and not things like their virtual environments, node modules, or compiled builds. Editors like vscode often do not include files that are .gitignored in their search either. pathspec is a pattern matching library that implements git [1]’s wildmatch pattern so that you can ignore files included in your .gitignore patterns. You might want this to help make your libraries more performant, or more intuitive for you users. import pathspec from pathlib import Path markdown_files = Path().glob('**/*.md') if (Path(".gitignore").exists(): lines = Path(".gitignore").read_text().splitlines() spec = pathspec.PathSpec.from_lines("gitwildmatch", lines) markdown_files = [ file for file in markdown_files if not spec.match_file(str(file)) ] pathspec home page [2] References: [1]: /glossary/git/ [2]: https://github.com/cpburnz/python-path-specification

I don’t use refactoring tools as much as I probably should. mostly because I work with small functions with unique names, but I recently had a case where a variable name m was everywhere and I wanted it named better. This was not possible with find and replace, because there were other m’s in this region. I first tried the nvim lsp rename, and it failed, Then I pip installed rope, a refactoring tool for python, and it just worked! pip install rope Once you have rope installed you can call rename on the variable. :lua vim.lsp.buf.rename()

When running a python process that requires a port it’s handy if there is an option for it to just run on the next avaialble port. To do this we can use the socket module to determine if the port is in use or not before starting our process. import socket def find_port(port=8000): """Find a port not in ues starting at given port""" with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s: if s.connect_ex(("localhost", port)) == 0: return find_port(port=port + 1) else: return port

Adding a --pdb flag to your applications can make them much easier for those using it to debug your application, especially if your applicatoin is a cli application where the user has much fewer options to start this for themselves. To add a pdb flag --pdb to your applications you will need to wrap your function call in a try/except, and start a post_mortem debugger. I give credit to this stack overflow post [1] for helping me figure this out. import pdb, traceback, sys def bombs(): a = [] print(a[0]) if __name__ == "__main__": if "--pdb" in sys.argv: try: bombs() except: extype, value, tb = sys.exc_info() traceback.print_exc() pdb.post_mortem(tb) else: bombs() Using –pdb # [2] python yourfile.py --pdb [3] References: [1]: https://stackoverflow.com/questions/242485/starting-python-debugger-automatically-on-error [2]: #using---pdb [3]: https://images.waylonwalker.com/using-pdb-flag-from-cli.png

Converting markdown posts to pdf on ubuntu takes a few packages from the standard repos. I had to go through a few stack overflow posts, and nothing seemed to have all the fonts and packages that I needed to convert markdown, but this is what ended up working for me. Installing all the packages # [1] sudo apt install \ pandoc \ texlive-latex-base \ texlive-fonts-recommended \ texlive-extra-utils \ texlive-latex-extra \ texlive-xetex Using pandoc to convert markdown to a pdf # [2] # older versions of pandoc, I needed this one on ubuntu 18.04 pandoc pages/til/convert-markdown-pdf-linux.md -o convert-markdown-pdf.pdf --latex-engine=xelatex # newer versions of pandoc, I needed this one on ubuntu 21.04 pandoc pages/til/convert-markdown-pdf-linux.md -o convert-markdown-pdf.pdf --pdf-engine=xelatex [3] Here is an image of what converting this article over to a pdf looks like. The raw markdown is here [4]. References: [1]: #installing-all-the-packages [2]: #using-pandoc-to-convert-markdown-to-a-pdf [3]: https://images.waylonwalker.com/convert-markdown-pdf-linux-result.png [4]: https://waylonwalker.com/convert-markdown-pdf-linux.md

Python comes with an enum module for creating enums. You can make your own enum by inheriting importing and inheriting from Enum. from enum import Enum class LifeCycle(Enum): configure = 1 glob = 2 pre_render = 3 render = 4 post_render = 5 save = 6 auto incrementing # [1] Enum values can be auto incremented by importing auto, and calling auto() as their value. from enum import Enum, auto class LifeCycle(Enum): configure = auto() glob = auto() pre_render = auto() render = auto() post_render = auto() save = auto() using the enum # [2] Enum’s are accessed directy under the class itself, and have primarily two methods underneath each thing you make, .name and .value. Lifecycle.glob Lifecycle.glob.value Lifecycle.glob.name [3] References: [1]: #auto-incrementing [2]: #using-the-enum [3]: https://images.waylonwalker.com/using-lifecycle-enum.png

I recently paired up with another dev running windows with Ubuntu running in wsl, and we had a bit of a stuggle to get our project off the ground because they were missing com system dependencies to get going. Straight in the terminal # [1] Open up a terminal and get your required system dependencies using the apt package manager and the standard ubuntu repos. sudo apt update sudo apt upgrade sudo apt install \ python3-dev \ python3-pip \ python3-venv \ python3-virtualenv pip install pipx Using an Ansible-Playbook # [2] I like running things like this through an ansible-playbook as it give me some extra control and repeatability next time I have a new machine to setup. - hosts: localhost gather_facts: true become: true become_user: "{{ lookup('env', 'USER') }}" pre_tasks: - name: update repositories apt: update_cache=yes become_user: root changed_when: False vars: user: "{{ ansible_user_id }}" tasks: - name: Install System Packages 1 (terminal) become_user: root apt: name: - build-essential - python3-dev - python3-pip - python3-venv - python3-virtualenv - name: check is pipx installed shell: command -v pipx register: pipx_exists ignore_errors: y...

Stow is an incredible way to manage your dotfiles. It works by managing symlinks between your dotfiles directory and the rest of the system. You can then make your dotfiles directory a git [1] repo and have it version controlled. In my honest opinion, when I was trying to get started the docs straight into deep detail of things I frankly don’t really care about and jumped right over how to use it. When using stow its easiest to keep your dotfiles directory (you may name it what you want) in your home directory, with application directories inside of it. Then each application directory should reflet the same diretory structure as you want in your home directory. zsh # [2] Here is a simple example with my zshrc. mkdir ~/dotfiles cd ~/dotfiles mkdir zsh mv ~/.zshrc zsh stow --simulate zsh You can pass in the –simulate if you wish, it will tell you if there are going to be any more errors or not, but it wont give much more than that. WARNING: in simulation mode so not modifying filesystem. Once your ready you can stow your zsh application. stow zsh nvim # [3] A slightly more complicated example is neovim since its diretory structure does not put configuration files directl...

The copier answers file is a key component to making your templates re-runnable. Let’s look at the example for my setup.py. ❯ tree ~/.copier-templates/setup.py /home/walkers/.copier-templates/setup.py ├── [[ _copier_conf.answers_file ]].tmpl ├── copier.yml ├── setup.cfg └── setup.py.tmpl 0 directories, 4 files Inside of my [[ _copier_conf.answers_file ]].tmpl file is this, a message not to muck around with it, and the ansers in yaml form. The first line is just a helper for the blog post. # ~/.copier-templates/setup.py/\[\[\ _copier_conf.answers_file\ \]\].tmpl # Changes here will be overwritten by Copier; NEVER EDIT MANUALLY [[_copier_answers|to_nice_yaml]] Inside my copier.yml I have setup my _answers_file to point to a special file. This is because this is not a whole projet template, but one just for a single file. # copier.yml # ... _answers_file: .setup-py-copier-answers.yml Once I change the _answers_file I was incredibly stuck Run it # [1] I’m making a library of personal copier templates in my ~/.copier-templates directory and I am going to run it from there. copier copy ~/.copier-templates/setup.py Results # [2] After rendering the template we have the followi...

Once you have made your sick looking cli apps with rich, eventually you are going to want to add some keybindings to them. Currently Textual, also written by @willmcgugan [1], does this extremely well. Fair Warning it is in super beta mode and expected to change a bunch. So take it easy with hopping on the train so fast. Get the things # [2] Install them from the command line. pip install textual pip install rich Import make a .py file and import them in it. from textual.app import App from textual.widget import Widget from rich.panel import Panel Make what you have a widget # [3] If you return your rich renderable out of class that inherits from textual.widget.Widget, you can then dock this inside of an app class inheriting from textual.app.App. class MyWidget(Widget): def render(self): my_renderable = Panel("press q to quit") return my_renderable class MyApp(App): async def on_mount(self) -> None: await self.view.dock(MyWidget(), edge="top") await self.bind("q", "quit") run it # [4] You’ve made a TUI (text user interface). Run the classmethod run to display the it in its full screen glory. MyApp.run(log="textual.log") Final result # [5] At this point It probabl...

I’ve been stuck many times looking at a vim buffer with little question marks at the beginning of each line and trying to get rid of them. for so long I didn’t know what they were so trying to get rid of them was impossible. [1] It turns out they are tabs, and you can get rid of the little leading question marks with this substitution command. :%s/\t/ /g References: [1]: https://images.waylonwalker.com/vim-tab-characters.png