{"id":7409,"date":"2020-09-22T08:16:09","date_gmt":"2020-09-22T06:16:09","guid":{"rendered":"https:\/\/pythonprogramming.altervista.org\/?p=7409"},"modified":"2020-11-06T18:20:42","modified_gmt":"2020-11-06T17:20:42","slug":"usage-of-python-decorators-example-nr-3","status":"publish","type":"post","link":"https:\/\/pythonprogramming.altervista.org\/usage-of-python-decorators-example-nr-3\/","title":{"rendered":"Usage of python decorators example nr. 3"},"content":{"rendered":"<p>This example shows a simple use of the <strong>decorators<\/strong> with python to add functionality to a function of\u00a0 a method without changing them. If you need to understande them well, take a look at these posts:<\/p>\n<ul>\n<li><a href=\"https:\/\/pythonprogramming.altervista.org\/python-decorators\/\">decorators<\/a> 1<\/li>\n<li><a href=\"https:\/\/pythonprogramming.altervista.org\/pythons-decorators-with-arguments\/\">decorators<\/a> 2<\/li>\n<li><a href=\"https:\/\/pythonprogramming.altervista.org\/usage-of-python-decorators-example-nr-3\/\">decorators 3<\/a> (this one)<\/li>\n<li><a href=\"https:\/\/pythonprogramming.altervista.org\/python-decorators-example-3-expanding-features\/\">decorators 4<\/a><\/li>\n<\/ul>\n<h2>Python decorator example<\/h2>\n<p>In this example you add some way to display some infos about a function, with a decorator, an external function that uses some data from the original function to add some features to it. The two functions that uses the same decorator (so you can save some code and make it more usable and re-usable) are made to just return a sum or a subtraction of two numbers. The decorator &#8216;decorate&#8217; the result printing the result in a more verbose way, explaining what the functions do.<\/p>\n<p>In this type of decorator, differently from the example we&#8217;ve see in the previous posts, we can pass an argument to the decorator, throught the &#8216;pie&#8217; symbol @dec&#8230; to call the decorator. In this way you can pass the &#8216;+&#8217; or &#8216;-&#8216; symbol to differentiate the output that fits the function that uses the same decorator.<\/p>\n<pre class=\"lang:default decode:true\">def dec(operator=\"\"):\r\n    def features(fn):\r\n        def add_some_decorations(a, b):\r\n            res = fn(a, b)\r\n            print(\"\\n\")\r\n            print(f\"Function: {fn.__name__}({a}, {b})\")\r\n            print(\"Operator: \", operator)\r\n            print(fn.__doc__, \":\", f\"{a} and {b}\")\r\n            print(\"Return: \", end=\"\")\r\n            print(f\"{a} {operator} {b}\")\r\n            print(f\"Output: \" + str(res))\r\n            return res\r\n        return add_some_decorations\r\n    return features\r\n\r\n\r\n@dec(operator=\"+\")\r\ndef add(a, b):\r\n    \"Addition of 2 arguments\"\r\n    return a + b\r\n\r\n\r\n@dec(operator=\"-\")\r\ndef sub(a, b):\r\n    \"Subtraction of 2 arguments\"\r\n    return a - b\r\n\r\n\r\nx = add(5, 2)\r\n\r\nx = sub(1, 4)\r\n<\/pre>\n<p>output<\/p>\n<pre class=\"lang:default decode:true \">Function: add(5, 2)\r\nOperator:  +\r\nAddition of 2 arguments : 5 and 2\r\nReturn: 5 + 2\r\nOutput: 7\r\n\r\n\r\nFunction: sub(1, 4)\r\nOperator:  -\r\nSubtraction of 2 arguments : 1 and 4\r\nReturn: 1 - 4\r\nOutput: -3<\/pre>\n<h2>First video tutorials about decorators<\/h2>\n<p><iframe loading=\"lazy\" title=\"Python decorators\" width=\"747\" height=\"560\" src=\"https:\/\/www.youtube.com\/embed\/C62Nu4yFFsM?feature=oembed&amp;enablejsapi=1\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<h2>Second video tutorial about decorators<\/h2>\n<p><iframe loading=\"lazy\" title=\"Python's decorators part 2 - Adding arguments\" width=\"747\" height=\"560\" src=\"https:\/\/www.youtube.com\/embed\/tNVm46aAIYQ?feature=oembed&amp;enablejsapi=1\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p>&nbsp;<\/p>\n<!-- se vuoi mettere un testo scorrevole\r\n[hoops name=\"typeWriterGen\"]\r\n\r\npoi metti un id diverso per ogni testo nella stessa pagina\r\n\r\n<div id=\"div01\">\r\n<script>\r\n\r\ntypeWriterGen(\"div01\",\"Esempio di testo scorrevole\");\r\n<\/script>\r\n\r\n-->\r\n<style>\r\n.avatar {\r\n  vertical-align: middle;\r\n  width: 100px;\r\n  height: 100px;\r\n  border-radius: 50%;\r\n}\r\n<\/style>\r\n\r\n<hr>\r\n\r\n<!-- NEWSLETTER LINK -->\r\n<a href=\"https:\/\/docs.google.com\/forms\/d\/e\/1FAIpQLSf7TniIPCWHDzCSGh2dYZaCwDvi9yLKS5ovFdKuK1sdfOvwEg\/viewform\">\r\n<img decoding=\"async\" src=\"https:\/\/pythonprogramming.altervista.org\/wp-content\/uploads\/2023\/08\/image-13.png\" class=\"avatar\">\r\nSubscribe to the <b>newsletter<\/b> for updates<\/a><br>\r\n\r\n<!-- TKINTER TEMPLATE LINK -->\r\n<a href=\"https:\/\/pythonprogramming.altervista.org\/tkinter-templates\/\">\r\n<img decoding=\"async\" src=\"https:\/\/i0.wp.com\/pythonprogramming.altervista.org\/wp-content\/uploads\/2023\/07\/image-26.png\" class=\"avatar\">\r\nTkinter templates<\/a><br>\r\n\r\n<!-- MY AVATAR PUT A LINK TO YOUTUBE CHANNEL-->\r\n<iframe loading=\"lazy\" frameborder=\"0\" src=\"https:\/\/itch.io\/embed\/711828\" width=\"552\" height=\"167\"><a href=\"https:\/\/pythonprogrammi.itch.io\/pysnake\">PySnake by PythonProgrammi<\/a><\/iframe>\r\n<br>\r\n<style>\r\n.avatar {\r\n  vertical-align: middle;\r\n  width: 100px;\r\n  height: 100px;\r\n  border-radius: 50%;\r\n}\r\n<\/style>\r\n\r\n\r\n<a href=\"https:\/\/www.youtube.com\/channel\/UCzbxq5e9gLiY-je2-br1rvg\">\r\n\t<img decoding=\"async\" src=\"https:\/\/pythonprogramming.altervista.org\/wp-content\/uploads\/2020\/10\/avatar64x64.png\" alt=\"Avatar\" class=\"avatar\">\r\n\t My youtube channel<\/a><br>\r\n\r\n<br>\r\n\r\nTwitter: <a href=\"https:\/\/twitter.com\/pythonprogrammi\">@pythonprogrammi - python_pygame<\/a>\r\n<h3>Claude's Games<\/h3>\r\n<p><a href=\"https:\/\/pythonprogramming.altervista.org\/random-daily-game-1-arkanoid\/\">Arkanoid<\/a><br>\r\n<a href=\"https:\/\/pythonprogramming.altervista.org\/platform-2d-with-pygame-made-with-claude\/\">Platform 2d<\/a><\/p> <!-- videogames made with claude -->\r\n<a href=\"https:\/\/pythonprogramming.altervista.org\/artifacts-games-day-1-memory-game\/\">1. Memory game<\/a>\r\n<h4>Videos<\/h4>\r\n<a href=\"https:\/\/youtu.be\/ciLjWWw5pLY\">Speech recognition game<\/a>\r\n<h3>Pygame's Platform Game<\/h3>\r\n\r\n<a href=\"https:\/\/pythonprogramming.altervista.org\/pygame-platform-game-5-sounds-and-mixer\/\"><img decoding=\"async\" src=\"https:\/\/i1.wp.com\/pythonprogramming.altervista.org\/wp-content\/uploads\/2020\/01\/climbercover.png?w=557&ssl=1\"\/ width=\"50%\"><\/a>\r\n<script>\r\nvar title = \"Platform Pygame\";\r\n\t\tvar links = [\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-animation-of-a-sprite-v-1-3\/\",\"Animation 1.3\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-sprite-animation-v-2-better-coding-test-it-checking-fps-on-the-screen\/\",\"Animation 1.2\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-how-to-display-the-frame-rate-fps-on-the-screen\/\",\"Display Frame rate\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-sprite-animation-update\/\",\"Animation 1.1\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-platformer-1\/\",\"Pygame Platform Game 1\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/python-platform-game-2\/\",\"Pygame Platform 2\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-platform-game-3-recap-cheatsheet\/\",\"Pygame PLatform 3 - recap and some Cheat Sheet\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-platform-game-4-background-and-stuffs\/\",\"Pygame Platform 4 - Background & organizing code\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-platform-game-5-sounds-and-mixer\/\",\"Pygame Platform 5 - Sounds\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/platform-game-in-detail-part-1\/\",\"Game in detail part 1\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/map-maker-1-2\/\", \"Map maker 1.2\"]\r\n\t\t];\r\n\t\t<\/script>\r\n<script>\r\n\t\r\nif (typeof next2 != \"undefined\"){let next2 = 0;}\r\n\t\r\nnext2 = 0;\r\n\thtml = \"\";\/\/<b style='color:coral;font-size:1.2em'>Other posts about \" + title + \"<\/b><br>\";\r\nfor (address of links) \r\n{\r\n\r\n\tif (next2 == 1){\r\n\t\thtml += \"<div style='background:coral'>\";\r\n\t\thtml += \"Next link => <a href='\" + address[0] + \"'>\" + address[1] + \"<\/a>\";\r\n\t\thtml += \"<\/div><br>\";\r\n\t\tnext2 = 0;\r\n\t}\r\n\tif (address[0] == document.URL) {\r\n\t\tnext2 = 1;\r\n\t}\r\n}\r\n\r\nif (typeof next != \"undefined\") {let next = 0;}\r\nif (typeof addressStart != \"undefined\") {let addressStart = \"\";}\r\nnext = 0;\r\naddressStart = \"<a href='\";\r\nfor (address of links) {\r\n\tif (next == 1){\r\n\t\thtml += \">>>\" + addressStart + address[0] + \"'>\" + address[1] + \"<\/a><br>\";\r\n\t\tnext = 0;\r\n\t}\r\n\telse if (addressStart + address[0] != document.URL)\r\n\t{\r\n\t\thtml += addressStart + address[0] + \"'>\" + address[1] + \"<\/a><br>\";\r\n\t}\r\n\telse\r\n\t{\r\n\t\tnext = 1;\r\n\t\tnext_address = address[0]\r\n\t\tnext_title = address[1]\r\n\t\thtml += \"<span style='color:gray'>\" + address[1] + \"<\/span><br>\";\r\n\t}\r\n\r\n}\r\n\r\n\thtml += `<span style=\"font-size:8px\">Powered by <a href=\"https:\/\/pythonprogramming.altervista.org\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2673\" src=\"https:\/\/pythonprogramming.altervista.org\/wp-content\/uploads\/2019\/06\/altervista2.png\" alt=\"\" width=\"70\" height=\"25\" srcset=\"https:\/\/pythonprogramming.altervista.org\/wp-content\/uploads\/2019\/06\/altervista2.png 156w, https:\/\/pythonprogramming.altervista.org\/wp-content\/uploads\/2019\/06\/altervista2-150x56.png 150w\" sizes=\"auto, (max-width: 70px) 100vw, 70px\" \/>pythonprogramming.altervista.org<\/a><\/span>`\r\n\thtml = \"<div style='background:yellow'>\" + html + \"<\/div>\";\r\n\tdocument.write(html)\r\n<\/script>\r\n\r\n<h3>Other Pygame's posts<\/h3>\r\n\r\n<script>\r\nvar title = \"Pygame's Posts\"\r\nvar links = [\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-platformer-1\/\",\"Platform game 1\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/make-a-platform-game-with-pygame-dafluffypotato\/\",\"DaFluffyPotato Platform Tutorials\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/python-and-classic-arcade-games-pong\/\",\"Pong Game Full\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/python-draws-in-colors-app-to-draw-with-pygame\/\",\"PyGameGIF 2\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-draw-app-with-animation\/\",\"PyGameGIF 1\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pydraw-2-0-app-to-draw-gif\/\",\"PyDraw 2.0\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-drawing-2\/\",\"Draw with Pygame\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/animation-with-pygame\",\"Sprite animation 1\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/animation-on-pygame-2-free-characters-and-more-actions\/\",\"Sprite animation 2\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/starting-with-pygame\/\",\"Starting movements with Pygame\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-3-move-sprite\/\", \"Move a Sprite\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-4-fonts\/\",\"Text and Fonts\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-animate-a-sprite\/\", \"Animate a sprite\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pygame-and-mouse-events\/\",\"Mouse events\"],\r\n[\"https:\/\/pythonprogramming.altervista.org\/pgp-aka-pygamepresentation-project\/\",\"Pygame presentation\"],\r\n\t[\"https:\/\/pythonprogramming.altervista.org\/moving-the-player-in-pygame-with-key-get_pressed\/\",\"How to use key.get_pressed()\"]\r\n]\r\n<\/script>\r\n\r\n\r\n<script>\r\n\t\r\nif (typeof next2 != \"undefined\"){let next2 = 0;}\r\n\t\r\nnext2 = 0;\r\n\thtml = \"\";\/\/<b style='color:coral;font-size:1.2em'>Other posts about \" + title + \"<\/b><br>\";\r\nfor (address of links) \r\n{\r\n\r\n\tif (next2 == 1){\r\n\t\thtml += \"<div style='background:coral'>\";\r\n\t\thtml += \"Next link => <a href='\" + address[0] + \"'>\" + address[1] + \"<\/a>\";\r\n\t\thtml += \"<\/div><br>\";\r\n\t\tnext2 = 0;\r\n\t}\r\n\tif (address[0] == document.URL) {\r\n\t\tnext2 = 1;\r\n\t}\r\n}\r\n\r\nif (typeof next != \"undefined\") {let next = 0;}\r\nif (typeof addressStart != \"undefined\") {let addressStart = \"\";}\r\nnext = 0;\r\naddressStart = \"<a href='\";\r\nfor (address of links) {\r\n\tif (next == 1){\r\n\t\thtml += \">>>\" + addressStart + address[0] + \"'>\" + address[1] + \"<\/a><br>\";\r\n\t\tnext = 0;\r\n\t}\r\n\telse if (addressStart + address[0] != document.URL)\r\n\t{\r\n\t\thtml += addressStart + address[0] + \"'>\" + address[1] + \"<\/a><br>\";\r\n\t}\r\n\telse\r\n\t{\r\n\t\tnext = 1;\r\n\t\tnext_address = address[0]\r\n\t\tnext_title = address[1]\r\n\t\thtml += \"<span style='color:gray'>\" + address[1] + \"<\/span><br>\";\r\n\t}\r\n\r\n}\r\n\r\n\thtml += `<span style=\"font-size:8px\">Powered by <a href=\"https:\/\/pythonprogramming.altervista.org\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2673\" src=\"https:\/\/pythonprogramming.altervista.org\/wp-content\/uploads\/2019\/06\/altervista2.png\" alt=\"\" width=\"70\" height=\"25\" srcset=\"https:\/\/pythonprogramming.altervista.org\/wp-content\/uploads\/2019\/06\/altervista2.png 156w, https:\/\/pythonprogramming.altervista.org\/wp-content\/uploads\/2019\/06\/altervista2-150x56.png 150w\" sizes=\"auto, (max-width: 70px) 100vw, 70px\" \/>pythonprogramming.altervista.org<\/a><\/span>`\r\n\thtml = \"<div style='background:yellow'>\" + html + \"<\/div>\";\r\n\tdocument.write(html)\r\n<\/script>\n<h2><\/h2>\n","protected":false},"excerpt":{"rendered":"Another example with python decorators\n<a class=\"moretag\" href=\"https:\/\/pythonprogramming.altervista.org\/usage-of-python-decorators-example-nr-3\/\"> [...]<\/a>","protected":false},"author":1,"featured_media":7413,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_crdt_document":"","footnotes":""},"categories":[210,912],"tags":[910],"class_list":["post-7409","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-basics","category-decorators","tag-decorators"],"avopt_banners_inside_post":true,"avopt_banners_on_page":true,"av_copy_from":"","av_sharing_message":"","av_sharing_allowed":true,"av_sharing_on":{"fb":[],"tw":[]},"av_allow_affiliate_banner":false,"av_allow_affiliate_multi_banner":false,"av_show_affiliation_buy_button":false,"av_post_rating":true,"av_have_post_rating_value":false,"av_is_artificial_intelligence_content":false,"_links":{"self":[{"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/posts\/7409","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/comments?post=7409"}],"version-history":[{"count":5,"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/posts\/7409\/revisions"}],"predecessor-version":[{"id":7629,"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/posts\/7409\/revisions\/7629"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/media\/7413"}],"wp:attachment":[{"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/media?parent=7409"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/categories?post=7409"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pythonprogramming.altervista.org\/wp-json\/wp\/v2\/tags?post=7409"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}