Python binary operators are pretty much the same as in any other language, however I notice most programmers tend to waste a lot of memory by creating lots and lots of properties say in DB tables, or Objects and using the wrong datatypes. I think its elegant to use the concept of binary flags, for example, if you have an object that has around 8 or 16 boolean properties, you can store their state in 1 byte or 2 bytes (1 char or 2 char fields), and turn on\/off the bits on those fields.<\/p>\n
Usually, if you have a binary field, and you want to, turn on bits, toggle bits, and check bits, you do the following.<\/p>\n
Suppose “config” is an 8 bit number, and you want to modify this bits individually, say config=4 (0b100) and you want to turn on the rightmost bit to have 0b101 (which is a 5) you could do the following<\/p>\n
\n>>> #Uses the | operator\n... def turnBitOn(config, binaryFlag):\n... return config | binaryFlag\n... \n>>> config = 4\n>>> config = turnBitOn(config,1)\n>>> print config\n5\n<\/pre>\nIf you want to check if a Bit is turned on, just use the “&” operator, if the result is the same as the bit you’re comparing, then its turned on.<\/p>\n
\n>>> def checkBit(config,binaryFlag):\n... return binaryFlag == config & binaryFlag\n... \n>>> print checkBit(config,1)\nTrue\n>>> print checkBit(config,2) #checks 0b010 in 0b101\nFalse\n<\/pre>\nWhat if you just want to toggle a bit, no matter what’s in there?
\nJust use binary XOR, the “^” operator.<\/p>\n\n>>> def toggleBit(config,binaryFlag):\n... return config ^ binaryFlag\n... \n>>> print config\n5\n>>> config = toggleBit(config,1)\n>>> print config\n4\n>>> config = toggleBit(config,1)\n>>> print config\n5\n<\/pre>\nAnd now, the last basic operation would be to turn off a bit. For this, you should do a NAND operation. The Binary Not in python as in most programming languages is the “~” operator. This is how you can use it to turn off bits.<\/p>\n
You have to do it in conjunction with the & operator, sort of doing a NAND<\/p>\n
\n>>> 5 & (~1)\n4\n>>> 5 &~ 1\n4\n<\/pre>\nSo we could define our turnOffBit function as follows:<\/p>\n
\n>>> def turnOffBit(config,binaryFlag):\n... return config & (~binaryFlag)\n... \n>>> print config\n5\n>>> config = turnOffBit(config,1)\n>>> print config\n4\n>>> config = turnOffBit(config,1)\n>>> print config\n4\n<\/pre>\nHope this makes a good reference for those trying to make the most out of their bytes.<\/p>\n","protected":false},"excerpt":{"rendered":"
Python binary operators are pretty much the same as in any other language, however I notice most programmers tend to waste a lot of memory by creating lots and lots of properties say in DB tables, or Objects and using the wrong datatypes. I think its elegant to use the concept of binary flags, for […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[15,30,43,65],"tags":[],"class_list":["post-557","post","type-post","status-publish","format-standard","hentry","category-code","category-geeklife","category-linux","category-python"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p5Unzf-8Z","jetpack-related-posts":[{"id":1526,"url":"https:\/\/www.gubatron.com\/blog\/droid-vs-nexus-1-sunspider-javascript-benchmark-showdown\/","url_meta":{"origin":557,"position":0},"title":"Droid vs Nexus 1 – SunSpider JavaScript Benchmark showdown","author":"gubatron","date":"January 10, 2010","format":false,"excerpt":"Nexus One runs JavaScript 2.32 times faster than the Motorola Droid. 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Since Android's\u2026","rel":"","context":"In "Code"","block_context":{"text":"Code","link":"https:\/\/www.gubatron.com\/blog\/category\/code\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":2749,"url":"https:\/\/www.gubatron.com\/blog\/deploying-html5-apps-on-cloudfront-with-efficient-invalidation-requests\/","url_meta":{"origin":557,"position":3},"title":"Deploying HTML5 apps on CloudFront with efficient invalidation requests","author":"gubatron","date":"June 8, 2012","format":false,"excerpt":"So you decided to build your next web app\/site using nothing but HTML5 and Javascript. No server side processing for anything related to UI. This means you will be coding a lot of JavaScript. Wouldn't it be nice to put all that static HTML and JS on your CloudFront CDN\u2026","rel":"","context":"In "Code"","block_context":{"text":"Code","link":"https:\/\/www.gubatron.com\/blog\/category\/code\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":744,"url":"https:\/\/www.gubatron.com\/blog\/new-safaris-javascript-engine-kicks-ass\/","url_meta":{"origin":557,"position":4},"title":"New Safari’s JavaScript engine Kicks Ass!","author":"gubatron","date":"March 19, 2008","format":false,"excerpt":"So I downloaded yesterday the latest Software Update for Mac OSX and it included an update of the Safari Web Browser, which I had taken for dead ages ago, I'm a hardcore Firefox user. 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