# til

My repo of Today I Learned posts. Inspired by [simonw/til](https://github.com/simonw/til).

## About This Repo

This repo is a living record of the technologies I've worked with and the problems I've solved. The topic list and dates tell you a lot about where my work has taken me.

I write these notes to document what I'm learning as I work (quickly, usually in under 10 minutes) with light proofreading. The goal is capture, not polish.

A few things this practice has taught me:
- Beginnerhood is perpetual.
- Breaking concepts into small pieces makes everything else — writing, teaching, debugging — easier.
- Some of these have been picked up by [Django News](https://django-news.com/issues/243?#start), which I'm proud of.

---

## Topics

<!-- toc starts -->
* [aws](#aws)
* [celery](#celery)
* [claude](#claude)
* [cloudflare](#cloudflare)
* [django](#django)
* [django-rest-framework](#django-rest-framework)
* [drf-yasg](#drf-yasg)
* [fast-ai](#fast-ai)
* [git](#git)
* [github](#github)
* [google](#google)
* [home-office](#home-office)
* [html](#html)
* [htmx](#htmx)
* [javascript](#javascript)
* [kubernetes](#kubernetes)
* [mac](#mac)
* [markdown](#markdown)
* [meilisearch](#meilisearch)
* [microsoft-dynamics](#microsoft-dynamics)
* [misc](#misc)
* [mkdocs](#mkdocs)
* [plata](#plata)
* [postgres](#postgres)
* [pre-commit](#pre-commit)
* [pytest](#pytest)
* [python](#python)
* [r](#r)
* [security](#security)
* [seo](#seo)
* [slack](#slack)
* [sphinx](#sphinx)
* [squarespace](#squarespace)
* [stripe](#stripe)
* [terraform](#terraform)
* [wagtail](#wagtail)
<!-- toc ends -->

---

<!-- index starts -->
### aws

* [AWS S3 and Boto3 Cheat Sheet](https://github.com/williln/til/blob/main/aws/s3_and_boto_and_minio.md) - 2024-03-18

### celery

* [Scheduling a nightly Celery task with Celery Beat](https://github.com/williln/til/blob/main/celery/schedule_nightly_task.md) - 2024-05-08

### claude

* [Creating a Basic Claude Code Skill](https://github.com/williln/til/blob/main/claude/claude-skills-basics.md) - 2026-03-12
* [Using `files-to-prompt` to generate an XML file for your Claude context](https://github.com/williln/til/blob/main/claude/files-to-prompt.md) - 2025-05-01
* [Using Claude Rules (`.claude/rules/`)](https://github.com/williln/til/blob/main/claude/using-claude-rules.md) - 2026-03-10

### cloudflare

* [Bot Fight Mode](https://github.com/williln/til/blob/main/cloudflare/bot-fight-mode.md) - 2025-04-29

### django

* [Adding a custom context processor to your Django app so you can include bits of data in your template headers more easily](https://github.com/williln/til/blob/main/django/add_context_processor.md) - 2024-05-29
* [Adding a custom field to the Django admin list display](https://github.com/williln/til/blob/main/django/custom_fields.md) - 2024-03-18
* [Adding a custom tag with `django-taggit`](https://github.com/williln/til/blob/main/django/django-taggit-custom-tag.md) - 2022-11-09
* [Adding ability to search in the Django Admin](https://github.com/williln/til/blob/main/django/add_search.md) - 2024-03-18
* [Adding extra fields to the list view in the Django Admin](https://github.com/williln/til/blob/main/django/add_fields_to_list_view.md) - 2024-03-18
* [Adding filtering functionality to the Django Admin](https://github.com/williln/til/blob/main/django/add_filtering.md) - 2024-03-18
* [Caching in Django Projects](https://github.com/williln/til/blob/main/django/caching.md) - 2023-04-19
* [Finding out how many objects have N connections to the other model in a M2M relationship](https://github.com/williln/til/blob/main/django/m2m_queries_how_many_objects_have_no_connections.md) - 2024-02-28
* [Finding the longest value of a particular field](https://github.com/williln/til/blob/main/django/longest_value_in_field.md) - 2024-02-28
* [Handling 404 Responses in Django](https://github.com/williln/til/blob/main/django/404_handling.md) - 2023-04-19
* [How I added a very simple django-streamfield example to a project](https://github.com/williln/til/blob/main/django/how_I_added_django_streamfield.md) - 2024-03-18
* [How I set up `django-activity-stream`, including a simple test](https://github.com/williln/til/blob/main/django/how_i_added_django_activity_stream_with_test.md) - 2024-03-25
* [How to confirm that login is required in your Django view](https://github.com/williln/til/blob/main/django/how_to_test_view_auth.md) - 2023-02-22
* [How to log in a test user in a `pytest` unit test](https://github.com/williln/til/blob/main/django/test_protected_page.md) - 2023-02-22
* [How to test a file upload with `pytest` and `SimpleUploadedFile`](https://github.com/williln/til/blob/main/django/testing_file_upload_pytest.md) - 2023-02-22
* [Neapolitan: Everything I've Learned](https://github.com/williln/til/blob/main/django/neapolitan.md) - 2024-08-01
* [Run SQL statements as part of your migrations with `migrations.RunSQL`](https://github.com/williln/til/blob/main/django/run_sql.md) - 2024-07-23
* [Testing Django signals, and disabling signals in tests (Django 2.2)](https://github.com/williln/til/blob/main/django/testing_django_signals.md) - 2020-07-27
* [Themes for the Django Admin](https://github.com/williln/til/blob/main/django/admin_themes.md) - 2025-04-25
* [Using `Coalesce` to provide a default value for `aggregate` queries](https://github.com/williln/til/blob/main/django/aggregation_coalesce.md) - 2021-02-18
* [Using `defer()` to limit the data you get from your models](https://github.com/williln/til/blob/main/django/defer.md) - 2022-10-19
* [Using `django-admin-env-notice` to add an envioronment notice to the frontend](https://github.com/williln/til/blob/main/django/add_env_banner_to_frontend.md) - 2024-06-20
* [Using `django-countries`](https://github.com/williln/til/blob/main/django/django_countries.md) - 2024-04-02
* [Using `iterator()` to loop through large querysets efficiently](https://github.com/williln/til/blob/main/django/iterator.md) - 2024-07-10
* [Using Django Aggregation](https://github.com/williln/til/blob/main/django/aggregation.md) - 2021-01-22
* [Using Enums in a Django Model ChoiceField (Django 2.2)](https://github.com/williln/til/blob/main/django/enums_as_choices.md) - 2020-05-26
* [Using inline formsets with `inlineformset_factory`](https://github.com/williln/til/blob/main/django/using_inline_formsets.md) - 2024-06-03
* [Why won't my Django file URLs come back signed from S3?](https://github.com/williln/til/blob/main/django/aws_signed_urls.md) - 2021-01-08

### django-rest-framework

* [Adding a custom pagination class to an action](https://github.com/williln/til/blob/main/django-rest-framework/custom_action_pagination.md) - 2022-10-25
* [Passing extra info in `context` to your DRF serializer](https://github.com/williln/til/blob/main/django-rest-framework/pass_to_context.md) - 2021-01-22

### drf-yasg

* [How to document your query parameters for `drf_yasg`](https://github.com/williln/til/blob/main/drf-yasg/query_params.md) - 2021-01-28
* [How to properly serialize a `serializer_method_field` with `drf_yasg`](https://github.com/williln/til/blob/main/drf-yasg/serializer_method_field.md) - 2021-01-28
* [How to serialize your request parameters for POST/PUT/PATCH requests](https://github.com/williln/til/blob/main/drf-yasg/define_request_body.md) - 2021-01-28

### fast-ai

* [Converting a `fastcore.basics.AttrDict` into a regular dictionary.](https://github.com/williln/til/blob/main/fast-ai/obj2dict.md) - 2024-03-18

### git

* [`git reset`, with `soft`: Undo your last commit but keep your changes](https://github.com/williln/til/blob/main/git/undo_commit_but_preserve_changes.md) - 2024-07-29
* [Checking out someone else's branch](https://github.com/williln/til/blob/main/git/check_out_remote_branch.md) - 2024-08-23
* [Moving from an old repo to a new repo in another organization](https://github.com/williln/til/blob/main/git/moving_to_a_new_repo.md) - 2024-05-13
* [Naming a `git stash` and re-applying it later](https://github.com/williln/til/blob/main/git/name_a_stash_and_apply_it.md) - 2024-10-17

### github

* [Commenting on an issue from a GitHub Action](https://github.com/williln/til/blob/main/github/gh-actions-comment-issue.md) - 2022-11-04
* [Creating a new file and committing it using a GitHub Action](https://github.com/williln/til/blob/main/github/gh-actions-step-to-create-and-commt-a-file.md) - 2022-11-04
* [Github Action that leaves a comment on new PRs or issues](https://github.com/williln/til/blob/main/github/action_pr_comment.md) - 2022-10-28
* [How to use a Github Action](https://github.com/williln/til/blob/main/github/howto_github_action.md) - 2020-05-26
* [Making one job in a workflow depend on another job](https://github.com/williln/til/blob/main/github/gh-actions-set-job-dependency.md) - 2022-11-04
* [Parsing JSON output from a GitHub Issue template in a GitHub Action](https://github.com/williln/til/blob/main/github/gh-actions-parse-json.md) - 2022-11-04
* [Running an action conditionally](https://github.com/williln/til/blob/main/github/gh-action-run-job-conditionally.md) - 2022-11-04
* [Running your tests with `pytest` in your PR via a GitHub Action](https://github.com/williln/til/blob/main/github/gh-action-test-ci.md) - 2024-07-24
* [Setting output for a step in a job, so a different job can use it](https://github.com/williln/til/blob/main/github/gh-action-set-output.md) - 2022-11-04
* [Temporarily disabling a GitHub action without touching the workflow file](https://github.com/williln/til/blob/main/github/gh_actions_temporary_disable.md) - 2022-11-07

### google

* [Using Google Cloud Service Accounts and authenticating as a dictionary (without the json file) in a Django project](https://github.com/williln/til/blob/main/google/using_service_account_as_dict.md) - 2024-03-01

### home-office

* [Troubleshooting my Brother HL-2270DW Wireless Printer](https://github.com/williln/til/blob/main/home-office/printer.md) - 2024-03-18

### html

* [Creating responsive images with `srcset`, `sizes`, and `<picture>`](https://github.com/williln/til/blob/main/html/responsive_images_with_picture_element.md) - 2024-06-05
* [Stop search engines from indexing your site and showing it in search results](https://github.com/williln/til/blob/main/html/stop_google_from_indexing_your_site.md) - 2024-06-12

### htmx

* [Making a simple `hx-get` request](https://github.com/williln/til/blob/main/htmx/making_an_hxget_request.md) - 2024-05-16
* [Updating other elements on the page with `hx-swap-oob`](https://github.com/williln/til/blob/main/htmx/out_of_band_swaps.md) - 2024-06-03

### javascript

* [TimelineJS for building interactive timelines from spreadsheet or JSON](https://github.com/williln/til/blob/main/javascript/timelinejs.md) - 2024-05-22

### kubernetes

* [Accessing a Kubernetes cluster for the first time](https://github.com/williln/til/blob/main/kubernetes/accessing_cluster.md) - 2024-05-14
* [Setting up Kubernetes access on MacOS with a config file](https://github.com/williln/til/blob/main/kubernetes/setting_up_new_access_mac.md) - 2024-05-14
* [Viewing logs for your pod](https://github.com/williln/til/blob/main/kubernetes/viewing_logs.md) - 2024-07-30

### mac

* [Control when your laptop locks, turns off the display, etc.](https://github.com/williln/til/blob/main/mac/control_when_machine_locks.md) - 2024-05-22

### markdown

* [Making a collapsible markdown section](https://github.com/williln/til/blob/main/markdown/collapsible_markdown.md) - 2022-11-05

### meilisearch

* [Securing Meilisearch with Docker for local Django development](https://github.com/williln/til/blob/main/meilisearch/securing_meilisearch_in_docker.md) - 2024-04-04
* [Securing the Meilisearch search itself](https://github.com/williln/til/blob/main/meilisearch/securing_meilisearch_search.md) - 2024-04-05
* [Setting up Meilisearch with Python, Docker, and Compose for local development](https://github.com/williln/til/blob/main/meilisearch/setting_up_meilisearch_python_docker.md) - 2024-04-04

### microsoft-dynamics

* [About Microsoft Dynamics](https://github.com/williln/til/blob/main/microsoft-dynamics/about-microsoft-dynamics.md) - 2024-05-29

### misc

* [Relume Design League - competitive web design](https://github.com/williln/til/blob/main/misc/competitive_web_design.md) - 2022-11-05

### mkdocs

* [Including your project's README on your MkDocs index page](https://github.com/williln/til/blob/main/mkdocs/include_readme_in_index.md) - 2024-07-08

### plata

* [[`plata`](https://github.com/matthiask/plata/) order processors](https://github.com/williln/til/blob/main/plata/processors.md) - 2024-10-01

### postgres

* [Collecting statistics about your database with `ANALYZE`](https://github.com/williln/til/blob/main/postgres/analyze.md) - 2024-07-23

### pre-commit

* [Setting up `pre-commit` in a new project](https://github.com/williln/til/blob/main/pre-commit/setup.md) - 2024-06-28

### pytest

* [Test that an exception is raised](https://github.com/williln/til/blob/main/pytest/assert_raises.md) - 2023-03-02

### python

* [`typing.final`](https://github.com/williln/til/blob/main/python/typing-final.md) - 2025-03-04
* [ChatGPT-4 distills the Python `mailbox` docs for me.](https://github.com/williln/til/blob/main/python/mailbox.md) - 2023-04-24
* [Create a new Python virtual environment/ pyenv cheat sheet](https://github.com/williln/til/blob/main/python/new-virtualenv.md) - 2022-10-14
* [Generate a markdown file with a table of contents in Python](https://github.com/williln/til/blob/main/python/generate-toc.md) - 2022-10-28
* [Generating a clickable table-of-contents for each directory in my TILs](https://github.com/williln/til/blob/main/python/generate_toc_for_subdirectory.md) - 2024-06-03
* [How to sort a Python dictionary by key or value](https://github.com/williln/til/blob/main/python/sort_dictionary.md) - 2021-02-02
* [How to sort a Python dictionary by multiple values](https://github.com/williln/til/blob/main/python/sort_dict_multiple_keys.md) - 2021-02-02
* [Using `Decimal.quantize`](https://github.com/williln/til/blob/main/python/decimal_quantize.md) - 2024-07-05
* [Using `pip-tools` and `pip-compile` for Python dependency management](https://github.com/williln/til/blob/main/python/pip_tools.md) - 2024-07-17

### r

* [`taylor`: The Taylor Swift / R Project](https://github.com/williln/til/blob/main/r/taylor_swift.md) - 2023-04-21
* [How to convert an `.rda` file to JSON](https://github.com/williln/til/blob/main/r/convert_rda_to_json.md) - 2023-04-21

### security

* [The EICAR Test File](https://github.com/williln/til/blob/main/security/eicar_test_file.md) - 2026-03-13

### seo

* [Google SEO Notes for eCommerce](https://github.com/williln/til/blob/main/seo/seo-ecommerce.md) - 2025-04-21

### slack

* [Keep Slack from kicking you out of huddles when your machine locks](https://github.com/williln/til/blob/main/slack/computer_locking_kicks_out_of_huddles.md) - 2024-05-22

### sphinx

* [Running Sphinx docs locally](https://github.com/williln/til/blob/main/sphinx/running_locally.md) - 2024-07-15

### squarespace

* [Export Your Squarespace Site to XML](https://github.com/williln/til/blob/main/squarespace/export-to-xml.md) - 2025-04-21

### stripe

* [`dj-stripe` contains models for all the Stripe objects and can sync them for you](https://github.com/williln/til/blob/main/stripe/setup-dj-stripe.md) - 2024-07-18
* [Creating a PaymentIntent, but not capturing it, and allowing more to be charged later](https://github.com/williln/til/blob/main/stripe/uncaptured_payment_intents_and_overcapture.md) - 2024-06-10
* [Generating a `PaymentIntent` and saving it to a Django model](https://github.com/williln/til/blob/main/stripe/payment_intents.md) - 2024-06-06
* [Receiving Stripe webhooks via `dj-stripe` in local dev](https://github.com/williln/til/blob/main/stripe/using_dj_stripe_webhooks_locally.md) - 2024-07-19
* [Setting up a webhook in local development (Django project)](https://github.com/williln/til/blob/main/stripe/webhook_local_dev.md) - 2024-07-11
* [Using off-session payments and `setup_future_usage`](https://github.com/williln/til/blob/main/stripe/off_session_payments.md) - 2024-06-06

### terraform

* [About Terraform and .tfvars files](https://github.com/williln/til/blob/main/terraform/tfvars-files.md) - 2024-07-15

### wagtail

* [Add Wagtail to an existing Django project](https://github.com/williln/til/blob/main/wagtail/add_to_existing_project.md) - 2024-02-26
* [Adding a Wagtail image programmatically](https://github.com/williln/til/blob/main/wagtail/add_image_programmatically.md) - 2024-07-01
* [Cheat Sheet for Wagtail StreamField](https://github.com/williln/til/blob/main/wagtail/cheat_sheet_wagtail_streamfield.md) - 2024-02-26
* [Cheat Sheet: Wagtail Page Model Fields](https://github.com/williln/til/blob/main/wagtail/cheat_sheet_wagtail_page_model_fields.md) - 2024-02-26
* [Choosing Between Wagtail Page Models and Django Models](https://github.com/williln/til/blob/main/wagtail/choosing_wagtail_page_models_vs_django_models.md) - 2024-02-26
* [Create a Custom Nested Block for Wagtail StreamField](https://github.com/williln/til/blob/main/wagtail/create_custom_nested_block_for_streamfield.md) - 2024-02-26
* [Creating Custom StreamField Blocks](https://github.com/williln/til/blob/main/wagtail/create_custom_streamfield_block.md) - 2024-02-26
* [Creating Wagtail pages with Streamfield content programmatically](https://github.com/williln/til/blob/main/wagtail/creating_streamfield_content_programmatically.md) - 2024-05-15
* [Example of linking Django models to Wagtail Page models](https://github.com/williln/til/blob/main/wagtail/example_integrating_wagtail_page_models_into_django_models.md) - 2024-02-26
* [Seeding my Wagtail site](https://github.com/williln/til/blob/main/wagtail/seeding_wagtail_site.md) - 2024-03-27
* [wagtail-jetstream](https://github.com/williln/til/blob/main/wagtail/wagtail-jetstream.md) - 2025-04-25
* [What to do if you delete the default Wagtail homepage](https://github.com/williln/til/blob/main/wagtail/fix_deleted_root_page.md) - 2024-03-25
<!-- index ends -->

<!-- docs-section starts -->

## Automatic README Generation

This repository uses GitHub Actions to automatically generate and update README files:

1. The main README.md (this file) is updated with:
   - A table of contents listing all topics
   - An index of all TIL posts organized by topic

2. Each subdirectory also gets its own README.md with links to all files in that directory.

These updates happen automatically whenever changes are pushed to the main branch.

<!-- docs-section ends -->