Subscribe

Python map() function

โœ๏ธ

How to use the map() function in Python

5 Jun, 2021 ยท 2 min read

After looking into the Python filter function, let's take a look at how the map works.

As we learned, the filter will return a section of the input based on certain criteria.

Map() function in Python

Let's first have a look at the syntax:

result = map(myFunction, input)

To give more details to this:

  • result: Is the output. This will be a changed sequence.
  • filter: Is the Python built-in function
  • myFunction: This will be a custom function we are going to build
  • input: This is the original sequence we want to map

As you can see, the syntax looks like the filter function. The main change will be inside the myFunction.

Let's say we have a list of numbers that we need to multiply by themselves.

input = [2, 5, 10]

def myFunction(n):
    return n * n

result = map(myFunction, input)
print(list(result))

# [4, 25, 100]

Pretty cool right, and like the filter one, we can use Lambda functions to make it even shorter.

input = [2, 5, 10]

result = map(lambda n: n * n, input)
print(list(result))

# [4, 25, 100]

Thank you for reading, and let's connect!

Thank you for reading my blog. Feel free to subscribe to my email newsletter and connect on Facebook or Twitter

Spread the knowledge with fellow developers on Twitter
Tweet this tip
Powered by Webmentions - Learn more

Read next ๐Ÿ“–

Speedtest your connection in Python

21 Jun, 2021 ยท 2 min read

Speedtest your connection in Python

F-strings in Python

7 Jun, 2021 ยท 2 min read

F-strings in Python

Join <html><head><script data-ezscrex='false' data-cfasync='false' data-pagespeed-no-defer>var __ez=__ez||{};__ez.stms=Date.now();__ez.evt={};__ez.script={};__ez.ck=__ez.ck||{};__ez.template={};__ez.template.isOrig=true;__ez.queue=function(){var e=0,i=0,t=[],n=!1,s=[],r=[],o=!0,a=function(e,i,n,s,r,o,a){var l=this;this.name=e,this.funcName=i,this.parameters=null===n?null:n instanceof Array?n:[n],this.isBlock=s,this.blockedBy=r,this.deleteWhenComplete=o,this.isError=!1,this.isComplete=!1,this.isInitialized=!1,this.proceedIfError=a,this.isTimeDelay=!1,this.process=function(){u("... func = "+e),l.isInitialized=!0,l.isComplete=!0,u("... func.apply: "+e);var i=l.funcName.split("."),n=null;i.length>3||(n=3===i.length?window[i[0]][i[1]][i[2]]:2===i.length?window[i[0]][i[1]]:window[l.funcName]),null!=n&&n.apply(null,this.parameters),!0===l.deleteWhenComplete&&delete t[e],!0===l.isBlock&&(u("----- F'D: "+l.name),f())}},l=function(e,i,t,n,s,r,o){var a=this;this.name=e,this.path=i,this.async=s,this.defer=r,this.isBlock=t,this.blockedBy=n,this.isInitialized=!1,this.isError=!1,this.isComplete=!1,this.proceedIfError=o,this.isTimeDelay=!1,this.isPath=function(e){return"/"===e[0]&&"/"!==e[1]},this.getSrc=function(e){return void 0!==window.__ezScriptHost&&this.isPath(e)?window.__ezScriptHost+e:e},this.process=function(){a.isInitialized=!0,u("... file = "+e);var i=document.createElement("script");i.src=this.getSrc(this.path),!0===s?i.async=!0:!0===r&&(i.defer=!0),i.onerror=function(){u("----- ERR'D: "+a.name),a.isError=!0,!0===a.isBlock&&f()},i.onreadystatechange=i.onload=function(){var e=i.readyState;u("----- F'D: "+a.name),e&&!/loaded|complete/.test(e)||(a.isComplete=!0,!0===a.isBlock&&f())},document.getElementsByTagName("head")[0].appendChild(i)}},c=function(e,i){this.name=e,this.path="",this.async=!1,this.defer=!1,this.isBlock=!1,this.blockedBy=[],this.isInitialized=!0,this.isError=!1,this.isComplete=i,this.proceedIfError=!1,this.isTimeDelay=!1,this.process=function(){}};function d(e){!0!==h(e)&&0!=o&&e.process()}function h(e){if(!0===e.isTimeDelay&&!1===n)return u(e.name+" blocked = TIME DELAY!"),!0;if(e.blockedBy instanceof Array)for(var i=0;i<e.blockedBy.length;i++){var s=e.blockedBy[i];if(!1===t.hasOwnProperty(s))return u(e.name+" blocked = "+s),!0;if(!0===e.proceedIfError&&!0===t[s].isError)return!1;if(!1===t[s].isComplete)return u(e.name+" blocked = "+s),!0}return!1}function u(e){var i=window.location.href,t=new RegExp("[?&]ezq=([^&#]*)","i").exec(i);"1"===(t?t[1]:null)&&console.debug(e)}function f(){++e>200||(u("let's go"),m(s),m(r))}function m(e){for(var i in e)if(!1!==e.hasOwnProperty(i)){var t=e[i];!0===t.isComplete||h(t)||!0===t.isInitialized||!0===t.isError?!0===t.isError?u(t.name+": error"):!0===t.isComplete?u(t.name+": complete already"):!0===t.isInitialized&&u(t.name+": initialized already"):t.process()}}return window.addEventListener("load",(function(){setTimeout((function(){n=!0,u("TDELAY -----"),f()}),5e3)}),!1),{addFile:function(e,i,n,o,a,c,h,u){var f=new l(e,i,n,o,a,c,h);!0===u?s[e]=f:r[e]=f,t[e]=f,d(f)},addDelayFile:function(e,i){var n=new l(e,i,!1,[],!1,!1,!0);n.isTimeDelay=!0,u(e+" ... FILE! TDELAY"),r[e]=n,t[e]=n,d(n)},addFunc:function(e,n,o,l,c,h,u,f,m){!0===h&&(e=e+"_"+i++);var p=new a(e,n,o,l,c,u,f);!0===m?s[e]=p:r[e]=p,t[e]=p,d(p)},addDelayFunc:function(e,i,n){var s=new a(e,i,n,!1,[],!0,!0);s.isTimeDelay=!0,u(e+" ... FUNCTION! TDELAY"),r[e]=s,t[e]=s,d(s)},items:t,processAll:f,setallowLoad:function(e){o=e},markLoaded:function(e){if(e&&0!==e.length){if(e in t){var i=t[e];!0===i.isComplete?u(i.name+" "+e+": error loaded duplicate"):(i.isComplete=!0,i.isInitialized=!0)}else t[e]=new c(e,!0);u("markLoaded dummyfile: "+t[e].name)}},logWhatsBlocked:function(){for(var e in t)!1!==t.hasOwnProperty(e)&&h(t[e])}}}();__ez.evt.add=function(e,t,n){e.addEventListener?e.addEventListener(t,n,!1):e.attachEvent?e.attachEvent("on"+t,n):e["on"+t]=n()},__ez.evt.remove=function(e,t,n){e.removeEventListener?e.removeEventListener(t,n,!1):e.detachEvent?e.detachEvent("on"+t,n):delete e["on"+t]};__ez.script.add=function(e){var t=document.createElement("script");t.src=e,t.async=!0,t.type="text/javascript",document.getElementsByTagName("head")[0].appendChild(t)};__ez.dot={};__ez.queue.addFile('/detroitchicago/boise.js', '/detroitchicago/boise.js?gcb=195-0&cb=2', true, [], true, false, true, false);__ez.queue.addFile('/detroitchicago/memphis.js', '/detroitchicago/memphis.js?gcb=195-0&cb=21', true, [], true, false, true, false);__ez.queue.addFile('/detroitchicago/minneapolis.js', '/detroitchicago/minneapolis.js?gcb=195-0&cb=4', true, [], true, false, true, false);__ez.queue.addFile('/detroitchicago/rochester.js', '/detroitchicago/rochester.js?gcb=195-0&cb=13', false, ['/detroitchicago/memphis.js','/detroitchicago/minneapolis.js'], true, false, true, false);!function(){var e;__ez.vep=(e=[],{Add:function(i,t){__ez.dot.isDefined(i)&&__ez.dot.isValid(t)&&e.push({type:"video",video_impression_id:i,domain_id:__ez.dot.getDID(),t_epoch:__ez.dot.getEpoch(0),data:__ez.dot.dataToStr(t)})},Fire:function(){if(void 0===document.visibilityState||"prerender"!==document.visibilityState){if(__ez.dot.isDefined(e)&&e.length>0)for(;e.length>0;){var i=5;i>e.length&&(i=e.length);var t=e.splice(0,i),o=__ez.dot.getURL("/detroitchicago/grapefruit.gif")+"?orig="+(!0===__ez.template.isOrig?1:0)+"&v="+btoa(JSON.stringify(t));__ez.dot.Fire(o)}e=[]}}})}();</script><script data-ezscrex='false' data-cfasync='false' data-pagespeed-no-defer>!function(){function e(i){return e="function"==typeof Symbol&&"symbol"==typeof Symbol.iterator?function(e){return typeof e}:function(e){return e&&"function"==typeof Symbol&&e.constructor===Symbol&&e!==Symbol.prototype?"symbol":typeof e},e(i)}__ez.pel=function(){var i=[];function t(t,o,d,_,n,r,a,s){if(__ez.dot.isDefined(t)&&0!=__ez.dot.isAnyDefined(t.getSlotElementId,t.ElementId)){void 0===s&&(s=!1);var p=parseInt(__ez.dot.getTargeting(t,"ap")),f=__ez.dot.getSlotIID(t),u=__ez.dot.getAdUnit(t,s),z=parseInt(__ez.dot.getTargeting(t,"compid")),g=0,c=0,l=function(i){if("undefined"==typeof _ezim_d)return!1;var t=__ez.dot.getAdUnitPath(i).split("/").pop();if("object"===("undefined"==typeof _ezim_d?"undefined":e(_ezim_d))&&_ezim_d.hasOwnProperty(t))return _ezim_d[t];for(var o in _ezim_d)if(o.split("/").pop()===t)return _ezim_d[o];return!1}(t);"object"==e(l)&&(void 0!==l.creative_id&&(c=l.creative_id),void 0!==l.line_item_id&&(g=l.line_item_id)),__ez.dot.isDefined(f,u)&&__ez.dot.isValid(o)&&("0"===f&&!0!==s||""===u||i.push({type:"impression",impression_id:f,domain_id:__ez.dot.getDID(),unit:u,t_epoch:__ez.dot.getEpoch(0),revenue:d,est_revenue:_,ad_position:p,ad_size:"",bid_floor_filled:n,bid_floor_prev:r,stat_source_id:a,country_code:__ez.dot.getCC(),pageview_id:__ez.dot.getPageviewId(),comp_id:z,line_item_id:g,creative_id:c,data:__ez.dot.dataToStr(o),is_orig:s||__ez.template.isOrig}))}}function o(){void 0!==document.visibilityState&&"prerender"===document.visibilityState||(__ez.dot.isDefined(i)&&i.length>0&&[i.filter((function(e){return e.is_orig})),i.filter((function(e){return!e.is_orig}))].forEach((function(e){for(;e.length>0;){var i=e[0].is_orig||!1,t=5;t>e.length&&(t=e.length);var o=e.splice(0,t),d=__ez.dot.getURL("/porpoiseant/army.gif")+"?orig="+(!0===i?1:0)+"&sts="+btoa(JSON.stringify(o));(void 0!==window.isAmp&&isAmp||void 0!==window.ezWp&&ezWp)&&void 0!==window._ezaq&&_ezaq.hasOwnProperty("domain_id")&&(d+="&visit_uuid="+_ezaq.visit_uuid),__ez.dot.Fire(d)}})),i=[])}return{Add:t,AddAndFire:function(e,i){t(e,i,0,0,0,0,0),o()},AddAndFireOrig:function(e,i){t(e,i,0,0,0,0,0,!0),o()},AddById:function(e,t,o,d){var _=e.split("/");if(__ez.dot.isDefined(e)&&3===_.length&&__ez.dot.isValid(t)){var n=_[0],r={type:"impression",impression_id:_[2],domain_id:__ez.dot.getDID(),unit:n,t_epoch:__ez.dot.getEpoch(0),pageview_id:__ez.dot.getPageviewId(),data:__ez.dot.dataToStr(t),is_orig:o||__ez.template.isOrig};void 0!==d&&(r.revenue=d),i.push(r)}},Fire:o,GetPixels:function(){return i}}}()}();__ez.queue.addFile('/detroitchicago/raleigh.js', '/detroitchicago/raleigh.js?gcb=195-0&cb=6', false, [], true, false, true, false);__ez.queue.addFile('/detroitchicago/tampa.js', '/detroitchicago/tampa.js?gcb=195-0&cb=5', false, [], true, false, true, false);</script> <script data-ezscrex="false" data-cfasync="false">(function(){if("function"===typeof window.CustomEvent)return!1;window.CustomEvent=function(c,a){a=a||{bubbles:!1,cancelable:!1,detail:null};var b=document.createEvent("CustomEvent");b.initCustomEvent(c,a.bubbles,a.cancelable,a.detail);return b}})();</script><script data-ezscrex="false" data-cfasync="false">__ez.queue.addFile('/detroitchicago/tulsa.js', '/detroitchicago/tulsa.js?gcb=195-0&cb=7', false, [], true, false, true, false);</script><script type="text/javascript">var ezouid = "1";</script><base href="https://sendy.daily-dev-tips.com/api/subscribers/active-subscriber-count.php"><script type='text/javascript'> var ezoTemplate = 'old_site_noads'; if(typeof ezouid == 'undefined') { var ezouid = 'none'; } var ezoFormfactor = '1'; var ezo_elements_to_check = Array(); </script> <script data-ezscrex="false" type='text/javascript'> var soc_app_id = '0'; var did = 408517; var ezdomain = 'daily-dev-tips.com'; var ezoicSearchable = 1; </script> <script data-ezscrex="false" type="text/javascript" data-cfasync="false">var _ezaq = {"ad_cache_level":0,"ad_lazyload_version":0,"ad_load_version":0,"city":"The Dalles","country":"US","days_since_last_visit":-1,"domain_id":408517,"engaged_time_visit":0,"ezcache_level":1,"ezcache_skip_code":8,"form_factor_id":1,"framework_id":1,"is_return_visitor":false,"is_sitespeed":0,"last_page_load":"","last_pageview_id":"","lt_cache_level":0,"metro_code":820,"page_ad_positions":"","page_view_count":0,"page_view_id":"2daf0911-6958-4839-7e19-1b83275532ea","position_selection_id":0,"postal_code":"97058","pv_event_count":0,"response_size_orig":4,"response_time_orig":288,"serverid":"34.219.211.72:15785","state":"OR","t_epoch":1669521655,"template_id":120,"time_on_site_visit":0,"url":"https://sendy.daily-dev-tips.com/api/subscribers/active-subscriber-count.php","user_id":0,"word_count":1,"worst_bad_word_level":0};var _ezExtraQueries = "&ez_orig=1";</script> <script data-ezscrex='false' data-pagespeed-no-defer data-cfasync='false'> function create_ezolpl(pvID, rv) { var d = new Date(); d.setTime(d.getTime() + (365*24*60*60*1000)); var expires = "expires="+d.toUTCString(); __ez.ck.setByCat("ezux_lpl_408517=" + new Date().getTime() + "|" + pvID + "|" + rv + "; " + expires, 3); } function attach_ezolpl(pvID, rv) { if (document.readyState === "complete") { create_ezolpl(pvID, rv); } if(window.attachEvent) { window.attachEvent("onload", create_ezolpl, pvID, rv); } else { if(window.onload) { var curronload = window.onload; var newonload = function(evt) { curronload(evt); create_ezolpl(pvID, rv); }; window.onload = newonload; } else { window.onload = create_ezolpl.bind(null, pvID, rv); } } } __ez.queue.addFunc("attach_ezolpl", "attach_ezolpl", ["2daf0911-6958-4839-7e19-1b83275532ea", "false"], false, ['/detroitchicago/boise.js'], true, false, false, false); </script></head><body>1894<script type='text/javascript' style='display:none;' async> __ez.queue.addFile('/detroitchicago/edmonton.webp', '/detroitchicago/edmonton.webp?a=a&cb=0&shcb=34', true, ['/detroitchicago/minneapolis.js'], true, false, false, false); __ez.queue.addFile('/porpoiseant/jellyfish.webp', '/porpoiseant/jellyfish.webp?a=a&cb=0&shcb=34', false, [], true, false, false, false); </script> <script>__ez.queue.addFile('/tardisrocinante/vitals.js', '/tardisrocinante/vitals.js?gcb=0&cb=3', false, ['/detroitchicago/minneapolis.js'], true, false, true, false);</script> <script type="text/javascript" data-cfasync="false"></script> <script>var _audins_dom="daily_dev_tips_com",_audins_did=408517;__ez.queue.addDelayFunc("audins.js","__ez.script.add", "//go.ezoic.net/detroitchicago/audins.js?cb=195-0");</script><noscript><div style="display:none;"><img src="//pixel.quantserve.com/pixel/p-31iz6hfFutd16.gif?labels=Domain.daily_dev_tips_com,DomainId.408517" border="0" height="1" width="1" alt="Quantcast"/></div></noscript> <script>__ez.queue.addFile('/beardeddragon/drake.js', '/beardeddragon/drake.js?gcb=0&cb=4', false, [], true, false, true, false);</script></body></html> devs and subscribe to my newsletter