| Sql QuerySet Notes | |
| SELECT count(*) FROM fruit Fruits.objects.count() table count | |
| SELECT count(*) FROM fruit WHERE name=’Orange’ Fruits.objects.filter(name__exact=’Orange’).count() count with filter | |
| SELECT * FROM fruit WHERE color is NULL Fruits.objects.get(color__isnull=True) filter by null | |
| SELECT * FROM fruit WHERE color is NOT NULL Fruits.objects.get(color__isnull=False) filter by null | |
| SELECT * FROM fruit WHERE name=’Apple’ Fruits.objects.get(name__exact=’Apple’) case sensitive | |
| SELECT * FROM fruit WHERE lower(name)=lower(‘Apple’) Fruits.objects.get(name__iexact=’Apple’) case in-sensitive | |
| SELECT * FROM fruit WHERE name LIKE ‘App%’ Fruits.objects.filter(name__startswith=’App’) case sensitive LIKE | |
| SELECT * FROM fruit WHERE upper(name) LIKE ‘APP%’ Fruits.objects.filter(name__ista |
| mr Marathi | |
| bs Bosnian | |
| ee_TG Ewe (Togo) | |
| ms Malay | |
| kam_KE Kamba (Kenya) | |
| mt Maltese | |
| ha Hausa | |
| es_HN Spanish (Honduras) | |
| ml_IN Malayalam (India) | |
| ro_MD Romanian (Moldova) |
| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
This is a plain-text version of Bret Victor’s reading list. It was requested by hf on Hacker News.
Highly recommended things!
This is my five-star list. These are my favorite things in all the world.
A few of these works have had an extraordinary effect on my life or way of thinking. They get a sixth star. ★
(by @andrestaltz)
If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.
| // Open-ended range operators | |
| // | |
| // 100... is equivalent to 100...Int.max | |
| // ...-100 is equivalent to Int.min...-100 | |
| // ..<3 is equivalent to Int.min..<3 | |
| import Swift | |
| /// Conforming types provide static `max` and `min` constants. | |
| protocol MinMaxType { |
Following the tradition from last year, here's my complete list of all interesting features and updates I could find in Apple's OSes, SDKs and developer tools that were announced at this year's WWDC. This is based on the keynotes, the "What's New In ..." presentations and some others, Apple's release notes, and blog posts and tweets that I came across in the last few weeks.
If for some reason you haven't watched the talks yet, I really recommend watching at least the "State of the Union" and the "What's New In" intros for the platforms you're interested in. The unofficial WWDC Mac app is great way to download the videos and keep track of what you've already watched.
If you're interested, here are my WWDC 2015 notes (might be useful if you're planning to drop support for iOS 8 now and start using some iOS 9 APIs).
| #!/bin/sh | |
| command="${*}" | |
| printf "Initialized REPL for `%s`\n" "$command" | |
| printf "%s> " "$command" | |
| read -r input | |
| while [ "$input" != "" ]; | |
| do | |
| eval "$command $input" | |
| printf "%s> " "$command" |
It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.
