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I-Web Scraping ne-Expert Semalt

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Ukukhwabanisa iwebhu, okubizwa nangokuthi kuvuna iwebhu, kuyindlela yokusebenzisa khipha idatha kusuka kumawebhusayithi. Isofthiwe yokuvuna iwebhu ingafinyelela kuwebhu ngokuqondile isebenzisa i-HTTP noma isiphequluli sewebhu. Ngenkathi inqubo ingase isetshenziswe ngesandla ngumsebenzisi we-software, le nqubo ngokuvamile ihlanganisa inqubo ezenzakalelayo esebenzayo esebenzisa i-web crawler noma i-bot.

I-Web scraping iyinkqubo lapho idatha ehleliwe ikopiwe kuwebhu ibe yindawo egciniwe yokubuyekezwa nokubuyisa. Kuhilela ukulanda ikhasi lewebhu bese lithatha okuqukethwe kwalo. Okuqukethwe kwekhasi kungasuswa, kusesha, kuhlelwa kabusha futhi idatha yayo ikopiwe kudivayisi yesitoreji sendawo.

Amakhasi eWebhu avame ukukhiwa ngezilimi ezisemthethweni ezisetshenziselwa umbhalo ezifana ne-XHTML ne-HTML, zombili eziqukethe idatha ewusizo ngendlela yokubhala. Noma kunjalo, amaningi alawa mawebhusayithi aklanyelwe abasebenzisi bokuphela kwabantu hhayi ngokusetshenziswa okuzenzakalelayo. Yingakho isofthiwe yokuqhafaza idalwe.

Kunezinkambiso eziningi ezingasetshenziselwa ukukhishwa kwewebhu ngokuphumelelayo. Ezinye zazo zichazwe ngezansi:

1. Ikhophi yomuntu-nokunamathisela

Ngezikhathi ezithile, ngisho nethuluzi elihle kunazo zonke lokuhlunga iwebhu alinakukufaka esikhundleni ukuchithwa nokusebenza kwekhophi yencwadi yomuntu kanye nokunamathisela..Lokhu kusebenza kakhulu ezimweni lapho amawebhusayithi ehlela izithiyo zokuvimbela umshini wokuzenzakalela.

2. Ukubumbana kwetheksthi yokulinganisa

Lena indlela elula kodwa enamandla esetshenziselwa ukukhipha idatha kumakhasi ewebhu. Kungase kusekelwe kumyalo we-UNIX grep noma nje isikhungo sokubonisa inkulumo yolwazi olunikezwayo, isibonelo, i-Python noma i-Perl.

3. HTTP Ukuhlela

HTTP Ukuhlela kungasetshenziswa kokubili amakhasi web static kanye ashukumisayo. Idatha ikhishwa ngokuthumela izicelo ze-HTTP kwisiphakeli sewebhu esisekude ngenkathi isebenzisa uhlelo lwe-socket.

4. I-HTML Ukuxoshwa

Amawebhusayithi amaningi athambekele ukuba neqoqo elibanzi lamakhasi adalwe ngokuzenzekelayo kusukela emthonjeni wesakhiwo esingaphansi kwe-database. Lapha, idatha engokwesigaba esifanayo ifakwe emakhosini afanayo. Ku-HTML ukuxubungula, uhlelo luvame ukubona isifanekiso esinjalo emthonjeni othile wolwazi, lithola okuqukethwe kwalo bese luyihumushela kwifomu elihlangene, elibizwa ngokuthi i-wrapper.

5. I-DOM parsing

Kule nqubo, uhlelo lokusebenza lufakwe kwisiphequluli sewebhu esiphelele njengeMozilla Firefox noma i-Inthanethi Explorer ukuthola okuqukethwe okunamandla okukhiqizwa yi-script-side script. Lezi ziphequluli zingaphinde zifake amakhasi ewebhu ngaphakathi komuthi we-DOM kuye ngokuthi izinhlelo ezingakhipha izingxenye zamakhasi.

6. Ukuqashelwa kwe-Annotation Annotation

Amakhasi ohlose ukuwaqamba angamukela ama-semantic markups kanye nezichasiselo noma imethadatha, engasetshenziselwa ukuthola imininingwana ethize yedatha. Uma lezi zichasiselo zifakwe emakhasini, le nqubo ingabhekwa njengesimo esikhethekile se-DOM parsing. Lezi zichasiselo zingabuye zihlelwe zibe ungqimba lwama-syntactic, bese zigcinwe futhi zilawulwe ngokwehlukana kumakhasi wewebhu. Ivumela ama-scrapers ukuthi athole i-schema yedatha kanye nemilayezo evela kulolu ungqimba ngaphambi kokuba ihlwithe amakhasi.

5 days ago
I-Web Scraping ne-Expert Semalt
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