adamchainz

# refactor of https://lukeplant.me.uk/blog/posts/double-checked-locking-with-django-orm/
# untested

def double_checked_lock_iterator(queryset):
    for item_pk in queryset.values_list("pk", flat=True):
        with transaction.atomic():
            try:
                yield queryset.select_for_update(skip_locked=True).get(id=item_pk)
            except queryset.model.DoesNotExist:
                pass

olljanat

param (
    [switch]$RenameOrphanLayers
)

If ($RenameOrphanLayers) {
	Write-Warning "$($env:COMPUTERNAME) -RenameOrphanLayers option enabled, will rename all orphan layers"
}

# Get known layers on Docker images
[array]$ImageDetails += docker images -q | ForEach { docker inspect $_ | ConvertFrom-Json }

pierrejoubert73

How to add a collapsible section in markdown

1. Example

Click me

Heading

1. Foo
2. Bar
   • Baz

• Qux

juanca

javascript:
document.querySelectorAll('.load-diff-button').forEach(node => node.click())

toolness

Adventures in Python Core Dumping

After watching Bryan Cantrill's presentation on [Running Aground: Debugging Docker in Production][aground] I got all excited (and strangely nostalgic) about the possibility of core-dumping server-side Python apps whenever they go awry. This would theoretically allow me to fully inspect the state of the program at the point it exploded, rather than relying solely on the information of a stack trace.

caseywatts

This is one chapter of my "Chrome Extension Workshops" tutorial, see the rest here: https://gist.github.com/caseywatts/8eec8ff974dee9f3b247

Unrelated update: my book is out! Debugging Your Brain is an applied psychology / self-help book

Making Bookmarklets

I'm feeling very clever. I've got this sweet line of javascript that replaces "cloud" with "butt". My mom would LOVE this, but she doesn't computer very well. I'm afraid to show her the Developer Console and have her type/paste this in. But she IS pretty good at bookmarks, she knows just how to click those!

A bookmark normally takes you to a new web page. A bookmarklet is a bookmark that runs javascript on the current page instead of taking you to a new page. To declare that it is a bookmarklet, the "location" it points to starts with javascript:.