Posts tagged: python

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...

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 [1]@willmcgugan [2], 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 # [3] 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 # [4] 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 # [5] 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 # [6] At this point It prob...

I was completely stuck for awhile. copier was not replacing my template variables. I found out that adding all these _endops fixed it. Now It will support all of these types of variable wrappers # copier.yml _templates_suffix: .jinja _envops: block_end_string: "%}" block_start_string: "{%" comment_end_string: "#}" comment_start_string: "{#" keep_trailing_newline: true variable_end_string: "}}" variable_start_string: "{{" !RTFM: Later I read the docs and realized that copier defaults to using [[ and ]] for its templates unlike other tools like cookiecutter.

I’ve been looking for a templating tool for awhile that works well with single files. My go to templating tool cookiecutter does not work for single files, it needs to put files into a directory underneath of it. template variables # [1] By default copier uses double square brackets for its variables. variables in files, directory_names, or file_names will be substituted for their value once you render them. # hello-py/hello.py.tmpl print('hello-[[name]]') note! by default copier will not inject variables into your template-strings unless you use a .tmpl suffix. Before running copier we need to tell copier what variables to ask for, we do this with a copier.yml file. # copier.yml name: default: my_name type: str help: What is your name installing copier # [2] I prefer to install cli tools that I need globally with pipx, this always gives me access to the tool without worrying about dependency conflicts, bloating my system site-packages, or managing a separate virtual environment [3] for it myself. pipx install copier running copier # [4] When running copier copy we pass in the directory of the template, and the directory that we want to render the template into. cop...

I just installed a brand new Ubuntu 21.10 Impish Indri, and wanted a kedro project to play with so I did what any good kedroid would do, I went to my command line and ran pipx run kedro new --starter spaceflights But what I got back was not what I expected! Fatal error from pip prevented installation. Full pip output in file: /home/walkers/.local/pipx/logs/cmd_2022-01-01_20.42.16_pip_errors.log Some possibly relevant errors from pip install: ERROR: Could not find a version that satisfies the requirement kedro (from versions: none) ERROR: No matching distribution found for kedro Error installing kedro. This is weird, why cant I run kedro new with pipx? Lets try pip. pip install kedro Same issue. ERROR: Could not find a version that satisfies the requirement kedro (from versions: none) ERROR: No matching distribution found for kedro What is Kedro [1] Curious what kedro is? Check out this article. What’s up # [2] wrong python version The issue is that kedro only runs on up to python 3.8, and on Ubuntu 21.10 when you apt install python3 you get python 3.9 and the standard repos don’t have an old enough version to run kedro. How to fix this? # [3] Theres a couple of wa...

Pluggy makes it so easy to allow users to modify the behavior of a framework without thier specific feature needing to be implemented in the framework itself. I’ve really been loving the workflow of frameworks built with pluggy. The first one that many python devs have experience with is pytest. I’ve never created a pytest plugin, and honestly at the time I looked into how they were made was a long time ago and it went over my head. I use a data pipelining framework called kedro, and have build many plugins for it. Making a plugin # [1] super easy to do As long as the framework document the hooks that are available and what it passes to them it’s so easy to make a plugin. Its just importing the hook_impl, making a class with a function that represents one of the hooks, and decorating it. from framework import hook_impl class LowerHook: @hook_impl def start(pluggy_example): pluggy_example.message = pluggy_example.message.lower() installing pluggy # [2] Installing pluggy is just like most python applications, install python, make your virtual environment [3], and pip install it. pip install pluggy Making a plugin driven framework # [4] much less easy At the time I sta...

pyenv provides an easy way to install almost any version of python from a large list of distributions. I have simply been using the version of python from the os package manager for awhile, but recently I bumped my home system to Ubuntu 21.10 impish, and it is only 3.9+ while the libraries I needed were only compatable with up to 3.8. I needed to install an older version of python on ubuntu I’ve been wanting to check out pyenv for awhile now, but without a burning need to do so. installing # [1] Based on the Readme it looked like I needed to install using homebrew,so this is what I did, but I later realized that there is a pyenv-installer repo that may have saved me this need. Installing Homebrew on Linux [2] List out install candidates # [3] You can list all of the available versions to install with pyenv install --list. It does reccomend updating pyenv if you suspect that it is missing one. At the time of writing this comes out to 532 different versions! pyenv install --list Let’s install the latest 3.8 patch # [4] Installing a version is as easy as pyenv install 3.8.12. This will install it, but not make it active anywhere. pyenv install 3.8.12 let’s use python 3.8...

Part of my neovim setup requires having the black python formatter installed and callable. I install it with pipx so that I don’t have to manage a virtual environment [1] and have it available everywhere. So far this works well for me, if there are ever breaking changes I may need to rethink this. re-installing a bunch of things that are already installed can be quite a waste and really add up to my ansible run time, so for most of my ansible tasks that install a command like this I have been following this pattern. - check if the command is installed with command -v <command> - register that step - ignore if that step fails - add a when: <xxx>_exists is failed condition to the step that installs that command. - name: check is black installed shell: command -v black register: black_exists ignore_errors: yes - name: install black when: black_exists is failed shell: pipx install black https://www.youtube.com/watch?v=MCFg6-W5SBI I made a video based on this post, check it out if its your thing References: [1]: /virtual-environment/

Adding a __render__ method that returns a rich renderable to any python class makes it display this output if printed with rich. This also includes being nested inside a rich Layout. import rich from rich.panel import Panel class ShowMe: def __rich__(self): return Panel("hello", border_style="gold1") if __name__ == "__main__": rich.print(ShowMe()) [1] References: [1]: https://images.waylonwalker.com/dunder_rich_showme.png