{"id":8091,"date":"2023-08-25T00:00:00","date_gmt":"2023-08-25T00:00:00","guid":{"rendered":"https:\/\/tech-lib.eu\/tech\/jak-vytezit-data-z-webovych-stranek-komplexni-pruvodce\/"},"modified":"2023-08-25T00:00:00","modified_gmt":"2023-08-25T00:00:00","slug":"jak-vytezit-data-z-webovych-stranek-komplexni-pruvodce","status":"publish","type":"post","link":"https:\/\/tech-lib.eu\/tech\/jak-vytezit-data-z-webovych-stranek-komplexni-pruvodce\/","title":{"rendered":"Jak vyt\u011b\u017eit data z webov\u00fdch str\u00e1nek. Komplexn\u00ed pr\u016fvodce"},"content":{"rendered":"
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Jak dostat data z webu?<\/div>\n
Vyberte Data > na\u010d\u00edst & transformovat > z webu. Stisknut\u00edm CTRL + V vlo\u017ete adresu URL do textov\u00e9ho pole a pak vyberte OK. V podokn\u011b navig\u00e1tor v \u010d\u00e1sti Mo\u017enosti zobrazen\u00edvyberte tabulku v\u00fdsledky . Power Query Zobraz\u00ed n\u00e1hled pro v\u00e1s v podokn\u011b zobrazen\u00ed tabulky vpravo. Cached<\/div>\n
\n\t\t\t\t\t Dal\u0161\u00ed informace najdete na<\/span> support.microsoft.com<\/a>\n\t\t\t\t<\/div>\n<\/p><\/div>\n
Web scraping, b\u011b\u017en\u011b ozna\u010dovan\u00fd jako data mining, je postup z\u00edsk\u00e1v\u00e1n\u00ed u\u017eite\u010dn\u00fdch informac\u00ed z webov\u00fdch str\u00e1nek. Zahrnuje z\u00edsk\u00e1v\u00e1n\u00ed informac\u00ed z online str\u00e1nek, jejich kategorizaci a pou\u017eit\u00ed v r\u016fzn\u00fdch anal\u00fdz\u00e1ch. V tomto \u010dl\u00e1nku se budeme zab\u00fdvat jednotliv\u00fdmi f\u00e1zemi vyt\u011b\u017eov\u00e1n\u00ed dat z webov\u00fdch str\u00e1nek, v\u010detn\u011b vyt\u011b\u017eov\u00e1n\u00ed v\u0161ech adres URL, vyu\u017eit\u00ed um\u011bl\u00e9 inteligence p\u0159i vyt\u011b\u017eov\u00e1n\u00ed webov\u00fdch str\u00e1nek, pou\u017eit\u00ed n\u00e1stroj\u016f pro vyt\u011b\u017eov\u00e1n\u00ed dat z webov\u00fdch str\u00e1nek a jednoduchosti vyt\u011b\u017eov\u00e1n\u00ed webov\u00fdch str\u00e1nek. <\/p>\n
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1. Z\u00edsk\u00e1n\u00ed v\u0161ech adres URL webov\u00fdch str\u00e1nek: <\/p>\n

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Ke scrapov\u00e1n\u00ed v\u0161ech adres URL z webov\u00fdch str\u00e1nek m\u016f\u017eete pou\u017e\u00edt n\u00e1sleduj\u00edc\u00ed postupy: a. Ur\u010dete c\u00edlovou webovou str\u00e1nku: Zvolte webovou str\u00e1nku, kterou chcete scrapovat, a p\u0159esn\u00e9 str\u00e1nky, ze kter\u00fdch chcete z\u00edskat data. b. Vyberte n\u00e1stroj pro scraping: Vyberte knihovnu nebo n\u00e1stroj pro \u0161kr\u00e1b\u00e1n\u00ed, kter\u00fd vyhovuje va\u0161im pot\u0159eb\u00e1m. Mezi obl\u00edben\u00e9 volby pat\u0159\u00ed Selenium, BeautifulSoup a Scrapy. – c. Prozkoumejte webov\u00e9 str\u00e1nky: Pomoc\u00ed funkce inspect element ve webov\u00e9m prohl\u00ed\u017ee\u010di se pod\u00edvejte na k\u00f3dov\u00e1n\u00ed HTML webov\u00e9 str\u00e1nky. To v\u00e1m umo\u017en\u00ed p\u0159esn\u011b ur\u010dit sou\u010d\u00e1sti, nap\u0159\u00edklad adresy URL, kter\u00e9 chcete se\u0161kr\u00e1bat. d. Vytvo\u0159te k\u00f3d pro se\u0161kr\u00e1b\u00e1n\u00ed: Pomoc\u00ed vybran\u00e9ho n\u00e1stroje pro \u0161kr\u00e1b\u00e1n\u00ed vytvo\u0159te k\u00f3d pro \u0161kr\u00e1b\u00e1n\u00ed, kter\u00fd nav\u0161t\u00edv\u00ed a extrahuje adresy URL z po\u017eadovan\u00fdch webov\u00fdch str\u00e1nek. K vyhled\u00e1n\u00ed a extrakci adres URL lze pou\u017e\u00edt v\u00fdrazy XPath nebo selektory CSS. Spus\u0165te n\u00e1sleduj\u00edc\u00ed k\u00f3d: Spus\u0165te k\u00f3d, kter\u00fd p\u0159im\u011bje scrapovac\u00ed n\u00e1stroj proch\u00e1zet str\u00e1nky webu a extrahovat zadan\u00e9 adresy URL. Zachycen\u00e9 adresy URL uschovejte pro pozd\u011bj\u0161\u00ed zpracov\u00e1n\u00ed nebo anal\u00fdzu. <\/p>\n

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Um\u00ed um\u011bl\u00e1 inteligence scrapovat online obsah? <\/p>\n

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Ano, pomoc\u00ed um\u011bl\u00e9 inteligence lze \u0161kr\u00e1bat webov\u00e9 str\u00e1nky. Algoritmy AI lze d\u00edky v\u00fdvoji v oblasti zpracov\u00e1n\u00ed p\u0159irozen\u00e9ho jazyka a strojov\u00e9ho u\u010den\u00ed vycvi\u010dit k inteligentn\u011bj\u0161\u00edmu ch\u00e1p\u00e1n\u00ed a zpracov\u00e1n\u00ed webov\u00fdch dat. \u0158e\u0161en\u00ed pro scraping webov\u00fdch str\u00e1nek poh\u00e1n\u011bn\u00e1 AI mohou automatizovat z\u00edsk\u00e1v\u00e1n\u00ed dat z webov\u00fdch str\u00e1nek, co\u017e vede k rychlej\u0161\u00edmu a efektivn\u011bj\u0161\u00edmu postupu. Tyto technologie mohou zvl\u00e1dat st\u00e1le n\u00e1ro\u010dn\u011bj\u0161\u00ed \u00falohy extrakce dat, p\u0159izp\u016fsobovat se zm\u011bn\u00e1m ve struktu\u0159e webov\u00fdch str\u00e1nek a dokonce zpracov\u00e1vat se\u0161kr\u00e1ban\u00e1 data pomoc\u00ed anal\u00fdzy sentimentu nebo rozpozn\u00e1v\u00e1n\u00ed obr\u00e1zk\u016f. <\/p>\n

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3. N\u00e1stroje pro anal\u00fdzu webov\u00fdch str\u00e1nek: N\u00e1stroje pro web mining jsou softwarov\u00e9 programy vytvo\u0159en\u00e9 speci\u00e1ln\u011b pro pot\u0159eby dolov\u00e1n\u00ed dat. Tyto n\u00e1stroje usnad\u0148uj\u00ed z\u00edsk\u00e1v\u00e1n\u00ed, \u00fapravu a anal\u00fdzu dat z webov\u00fdch str\u00e1nek. \u010casto nab\u00edzej\u00ed \u0159adu funkc\u00ed, v\u010detn\u011b proch\u00e1zen\u00ed webu, extrakce dat, \u010di\u0161t\u011bn\u00ed dat a vizualizace dat, spolu s p\u0159\u00edstupn\u00fdm u\u017eivatelsk\u00fdm rozhran\u00edm. Octoparse, ParseHub a Import.io jsou n\u011bkter\u00e1 zn\u00e1m\u00e1 \u0159e\u0161en\u00ed pro vyt\u011b\u017eov\u00e1n\u00ed webov\u00fdch str\u00e1nek. Tyto programy poskytuj\u00ed pokro\u010dil\u00e9 funkce pro zku\u0161en\u00e9 webminery i mo\u017enosti vhodn\u00e9 pro za\u010d\u00e1te\u010dn\u00edky. 4. Je web scraping jednoduch\u00fd na proveden\u00ed? Slo\u017eitost scrapovan\u00e9 str\u00e1nky a mno\u017estv\u00ed shroma\u017e\u010fovan\u00fdch dat maj\u00ed velk\u00fd vliv na to, jak jednoduch\u00e9 nebo obt\u00ed\u017en\u00e9 je web scraping. Nap\u0159\u00edklad extrakce textu nebo adres URL ze statick\u00fdch webov\u00fdch str\u00e1nek je snadn\u00fdm \u00fakolem web scrapingu. Slo\u017eit\u011bj\u0161\u00ed webov\u00e9 str\u00e1nky s dynamick\u00fdm obsahem, nap\u0159\u00edklad vytvo\u0159en\u00e9 pomoc\u00ed framework\u016f JavaScript, v\u0161ak mohou vy\u017eadovat sofistikovan\u011bj\u0161\u00ed metody a vybaven\u00ed. <\/p>\n

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Krom\u011b toho mohou webov\u00e9 str\u00e1nky stanovit omezen\u00ed pro scraping, nap\u0159\u00edklad nutnost ov\u011b\u0159en\u00ed nebo pou\u017eit\u00ed CAPTCHA \u010di blokov\u00e1n\u00ed IP adres jako n\u00e1stroj\u016f proti scrapov\u00e1n\u00ed. K p\u0159ekon\u00e1n\u00ed t\u011bchto p\u0159ek\u00e1\u017eek m\u016f\u017ee b\u00fdt nutn\u00e9 pou\u017e\u00edt v\u011bt\u0161\u00ed technick\u00e9 znalosti nebo specifick\u00e9 vybaven\u00ed. <\/p>\n

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Souhrnn\u011b lze \u0159\u00edci, \u017ee data mining a web scraping jsou \u00fa\u010dinn\u00e9 metody z\u00edsk\u00e1v\u00e1n\u00ed u\u017eite\u010dn\u00fdch informac\u00ed z webov\u00fdch str\u00e1nek. P\u0159i dodr\u017een\u00ed v\u00fd\u0161e uveden\u00fdch z\u00e1sad a pou\u017eit\u00ed vhodn\u00fdch n\u00e1stroj\u016f a technologi\u00ed m\u016f\u017eete efektivn\u011b t\u011b\u017eit data z webov\u00fdch str\u00e1nek pro nejr\u016fzn\u011bj\u0161\u00ed \u00fa\u010dely. Web scraping v\u00e1m m\u016f\u017ee nab\u00eddnout pronikav\u00e9 informace a podpo\u0159it v\u00e1s p\u0159i vytv\u00e1\u0159en\u00ed dob\u0159e informovan\u00fdch rozhodnut\u00ed na z\u00e1klad\u011b z\u00edskan\u00fdch dat, a\u0165 u\u017e jste v\u00fdzkumn\u00edk, datov\u00fd analytik nebo obchodn\u00ed expert.<\/p><\/div>\n

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FAQ<\/div>\n
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Je \u0161patn\u00e9 scrapovat webov\u00e9 str\u00e1nky?<\/div>\n

\u0160kr\u00e1b\u00e1n\u00ed webov\u00fdch str\u00e1nek je v z\u00e1vislosti na okolnostech a \u00fa\u010delu \u0161kr\u00e1b\u00e1n\u00ed bu\u010f pova\u017eov\u00e1no za \u0161kodliv\u00e9, nebo nen\u00ed hrozn\u00e9. \u0160kr\u00e1b\u00e1n\u00ed webov\u00fdch str\u00e1nek je \u010dasto pova\u017eov\u00e1no za neetick\u00e9 nebo dokonce nez\u00e1konn\u00e9, pokud poru\u0161uje podm\u00ednky slu\u017eby webov\u00fdch str\u00e1nek nebo pokud poru\u0161uje autorsk\u00e1 pr\u00e1va nebo z\u00e1kony o ochran\u011b osobn\u00edch \u00fadaj\u016f. <\/p>\n

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Pro \u0161kr\u00e1b\u00e1n\u00ed webov\u00fdch str\u00e1nek v\u0161ak existuj\u00ed etick\u00e1 a pr\u00e1vn\u00ed ospravedln\u011bn\u00ed. Nap\u0159\u00edklad akademi\u010dt\u00ed pracovn\u00edci mohou scrapovat webov\u00e9 str\u00e1nky, aby shrom\u00e1\u017edili informace pro akademick\u00e9 studie nebo aby sledovali vzory a trendy. Podniky mohou tak\u00e9 scrapovat webov\u00e9 str\u00e1nky, aby z\u00edskaly informace o konkurentech nebo z\u00edskaly voln\u011b p\u0159\u00edstupn\u00e9 \u00fadaje pro pr\u016fzkum trhu. <\/p>\n

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Nakonec je d\u016fle\u017eit\u00e9 p\u0159istupovat ke scrapov\u00e1n\u00ed webov\u00fdch str\u00e1nek obez\u0159etn\u011b a v mez\u00edch mor\u00e1lky a z\u00e1kona. Je rozumn\u00e9 prostudovat podm\u00ednky slu\u017eby pro webov\u00e9 str\u00e1nky, v p\u0159\u00edpad\u011b pot\u0159eby z\u00edskat povolen\u00ed a potvrdit, \u017ee operace scrapingu dodr\u017euj\u00ed v\u0161echny p\u0159\u00edslu\u0161n\u00e9 z\u00e1kony a pravidla. <\/p>\n<\/div>\n

\n
Jak z\u00edskat data z adresy URL pomoc\u00ed jazyka Python?<\/div>\n

Tyto kroky lze pou\u017e\u00edt k z\u00edsk\u00e1n\u00ed dat z adresy URL pomoc\u00ed jazyka Python: <\/p>\n

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1. P\u0159ineste po\u017eadovan\u00e9 knihovny: Nejprve importujte pot\u0159ebn\u00e9 knihovny. Pomoc\u00ed knihovny requests m\u016f\u017eete odes\u00edlat po\u017eadavky HTTP a z\u00edsk\u00e1vat obsah HTML pro web scraping a pomoc\u00ed knihovny BeautifulSoup m\u016f\u017eete analyzovat a extrahovat data z HTML. from bs4 import BeautifulSoup <\/p>\n

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“’python <\/p>\n

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import requests <\/p>\n

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„` <\/p>\n

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2. Kterou knihovnu pou\u017eijete? Prove\u010fte po\u017eadavek HTTP na n\u00e1sleduj\u00edc\u00ed adresu URL: Pro odesl\u00e1n\u00ed po\u017eadavku HTTP GET na adresu URL, kterou chcete se\u0161kr\u00e1bat, pou\u017eijte metodu ‚get()‘ z bal\u00ed\u010dku requests. url = „https:\/\/example.com“ <\/p>\n

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“’python <\/p>\n

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“‘ <\/p>\n

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response = requests.get(url) <\/p>\n

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“‘ <\/p>\n

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Nahra\u010fte adresou URL, kterou si p\u0159ejete se\u0161kr\u00e1bat. 3. Zadejte adresu URL, kterou chcete se\u0161kr\u00e1bat. Rozbor obsahu HTML: Po obdr\u017een\u00ed odpov\u011bdi pou\u017eijte BeautifulSoup k rozboru HTML. P\u0159edejte t\u011blo odpov\u011bdi a uve\u010fte parser HTML (nap\u0159\u00edklad „html.parser“). „“python“ soup = BeautifulSoup(response.content, „html.parser“) <\/p>\n

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„` <\/p>\n

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4. Extrakce po\u017eadovan\u00fdch dat: Pomoc\u00ed BeautifulSoup m\u016f\u017eete nyn\u00ed proch\u00e1zet a extrahovat po\u017eadovan\u00e1 data z HTML. K nalezen\u00ed ur\u010dit\u00fdch komponent HTML m\u016f\u017eete pou\u017e\u00edt \u0159adu technik, v\u010detn\u011b ‚find()‘, ‚find_all()‘ a selektor\u016f CSS. “’python“‘ <\/p>\n

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# P\u0159\u00edklad: V\u00fdb\u011br v\u0161ech zna\u010dek a> spolu s jejich atributy href pomoc\u00ed syntaxe: links = soup.find_all(„a“) for links, print (link.get(„href“)) <\/p>\n

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„` <\/p>\n

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5. Zpracujte nebo uchovejte informace: Z\u00edskan\u00e1 data pak m\u016f\u017eete zpracovat podle sv\u00fdch pot\u0159eb. Lze je uchov\u00e1vat v datab\u00e1zi, zapsat do souboru nebo je podrobit dal\u0161\u00edmu v\u00fdzkumu. <\/p>\n

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Toto je stru\u010dn\u00fd v\u00fdklad pou\u017eit\u00ed jazyka Python k z\u00edsk\u00e1n\u00ed dat z adresy URL. Je mo\u017en\u00e9, \u017ee budete muset upravit f\u00e1ze anal\u00fdzy a extrakce na z\u00e1klad\u011b rozvr\u017een\u00ed a slo\u017eitosti webov\u00e9 str\u00e1nky.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Jak dostat data z webu? Vyberte Data > na\u010d\u00edst & transformovat > z webu. Stisknut\u00edm CTRL + V vlo\u017ete adresu URL do textov\u00e9ho pole a pak vyberte OK. V podokn\u011b navig\u00e1tor v \u010d\u00e1sti Mo\u017enosti zobrazen\u00edvyberte tabulku v\u00fdsledky . Power Query Zobraz\u00ed n\u00e1hled pro v\u00e1s v podokn\u011b zobrazen\u00ed tabulky vpravo. Cached Dal\u0161\u00ed informace najdete na support.microsoft.com … \u010c\u00edst d\u00e1l<\/a><\/p>\n","protected":false},"author":3963,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3152],"tags":[],"class_list":["post-8091","post","type-post","status-publish","format-standard","hentry","category-data-mining"],"_links":{"self":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/8091","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/users\/3963"}],"replies":[{"embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/comments?post=8091"}],"version-history":[{"count":0,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/8091\/revisions"}],"wp:attachment":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/media?parent=8091"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/categories?post=8091"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/tags?post=8091"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}