Go language combines regular expressions to achieve efficient data acquisition

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"regexp"
)

func main() {
	// Send HTTP request	resp, err := ("")
	if err != nil {
		("HTTP request failed:", err)
		return
	}
	defer ()

	// Read the response content	body, err := ()
	if err != nil {
		("Read response failed:", err)
		return
	}

	// Compile regular expressions to match all A-label href attributes	re := (`<a[^>]+href=["'](.*?)["']`)
	matches := (string(body), -1)

	// Output all links	("Link Found:")
	for _, match := range matches {
		if len(match) > 1 {
			(match[1])
		}
	}
}

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"regexp"
)

func main() {
	resp, err := ("")
	if err != nil {
		("HTTP request failed:", err)
		return
	}
	defer ()

	body, _ := ()

	// Match all <h1>-<h6> tag content	re := (`&lt;h[1-6][^&gt;]*&gt;(.*?)&lt;/h[1-6]&gt;`)
	titles := (string(body), -1)

	("Web title:")
	for _, title := range titles {
		if len(title) &gt; 1 {
			// Remove HTML tags			cleanTitle := (`&lt;[^&gt;]+&gt;`).ReplaceAllString(title[1], "")
			(cleanTitle)
		}
	}
}

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"regexp"
	"strings"
)

func main() {
	resp, err := ("/table-page")
	if err != nil {
		("HTTP request failed:", err)
		return
	}
	defer ()

	body, _ := ()
	content := string(body)

	// Match the entire table	tableRe := (`<table[^>]*>(.*?)</table>`)
	tableMatch := (content)
	if len(tableMatch) == 0 {
		("Not found")
		return
	}

	tableContent := tableMatch[1]

	// Match table rows	rowRe := (`<tr[^>]*>(.*?)</tr>`)
	rows := (tableContent, -1)

	// Match cells	cellRe := (`<t[dh][^>]*>(.*?)</t[dh]>`)

	("Table Data:")
	for _, row := range rows {
		cells := (row[1], -1)
		for _, cell := range cells {
			if len(cell) > 1 {
				// Clean cell content				cleanCell := ((`<[^>]+>`).ReplaceAllString(cell[1], ""))
				("%s\t", cleanCell)
			}
		}
		() // Line break	}
}

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"regexp"
)

type Product struct {
	Name  string  `json:"name"`
	Price float64 `json:"price"`
}

func main() {
	resp, err := ("/products")
	if err != nil {
		("HTTP request failed:", err)
		return
	}
	defer ()

	body, _ := ()

	// Method 1: Directly parse JSON	var products []Product
	if err := (body, &products); err == nil {
		("Product List(JSONAnalysis):")
		for _, p := range products {
			("%s - $%.2f\n", , )
		}
		return
	}

	// Method 2: Use regularity when JSON structure is uncertain	("\nTry to use regular expression extraction:")

	// Match the product name and price	re := (`"name"\s*:\s*"([^"]+)"[^}]+"price"\s*:\s*(\d+\.?\d*)`)
	matches := (string(body), -1)

	for _, match := range matches {
		if len(match) >= 3 {
			("%s - $%s\n", match[1], match[2])
		}
	}
}

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"regexp"
	"sync"
)

func main() {
	urls := []string{
		"/page1",
		"/page2",
		"/page3",
	}

	var wg 
	semaphore := make(chan struct{}, 3) // Concurrency limit is 3
	titleRe := (`<title[^>]*>(.*?)</title>`)

	for _, url := range urls {
		(1)
		go func(u string) {
			defer ()
			semaphore <- struct{}{} // Get semaphore
			resp, err := (u)
			if err != nil {
				("Failed to obtain %s: %v\n", u, err)
				<-semaphore
				return
			}

			body, _ := ()
			()

			title := (string(body))
			if len(title) > 1 {
				("%s title: %s\n", u, title[1])
			}

			<-semaphore // Release the semaphore		}(url)
	}

	()
}

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"regexp"
	"strconv"
)

func main() {
	baseURL := "/news?page="
	pageRe := (`<div class="news-item">(.*?)</div>`)
	titleRe := (`<h2>(.*?)</h2>`)
	pageNumRe := (`page=(\d+)`)

	// Get the total number of pages first	totalPages := getTotalPages(baseURL + "1")
	
	("Total %d page content\n", totalPages)

	// Crawl content on each page	for page := 1; page <= totalPages; page++ {
		url := baseURL + (page)
		("\nCrawling page %d: %s\n", page, url)
		
		resp, err := (url)
		if err != nil {
			("Failed to obtain page %d: %v\n", page, err)
			continue
		}

		body, _ := ()
		()

		newsItems := (string(body), -1)
		for _, item := range newsItems {
			if len(item) > 1 {
				title := (item[1])
				if len(title) > 1 {
					("News Title:", title[1])
				}
			}
		}
	}
}

func getTotalPages(url string) int {
	resp, err := (url)
	if err != nil {
		return 1 // Default 1 page	}
	defer ()

	body, _ := ()
	
	// Suppose there is a text similar to "5 pages in total" on the page	re := (`common\s*(\d+)\s*Page`)
	match := (string(body))
	if len(match) > 1 {
		total, _ := (match[1])
		return total
	}
	
	return 1
}

client := &{}
req, _ := ("GET", "", nil)
("User-Agent", "Mozilla/5.0 (compatible; MyBot/1.0)")
resp, _ := (req)

import "net/url"

base, _ := ("")
rel, _ := ("/page1")
absURL := (rel).String()

resp, err := (url)
if err != nil {
    return ("Request failed: %w", err)
}
defer func() {
    if err := (); err != nil {
        ("Closing the response body failed: %v", err)
    }
}()

import "time"

func crawlWithDelay(urls []string, delay ) {
    for _, url := range urls {
        go crawlPage(url)
        (delay)
    }
}

proxyUrl, _ := ("http://proxy-ip:port")
client := &{
    Transport: &{
        Proxy: (proxyUrl),
    },
}
resp, _ := ("")

jar, _ := (nil)
client := &{Jar: jar}
// Get cookies for the first time("/login")
// Subsequent requests will carry cookies("/protected-page")