一、爬什么？
1、明确目标 ： 知道你准备在那个范围或者网站去搜索
2、爬： 将所有的网站的内容全部爬下来
3、取：去掉对我们没用处的数据
4、处理数据：按照我们想要的方式存储或使用
二、百度贴吧小爬虫
需求：百度贴吧，每50页就翻页
https://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=0
https://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=50
示例： 单线程版本
package main import (
"fmt"
"net/http"
"os"
"strconv"
) //爬取网页内容
func HttpGet(url string) (result string, err error) {
resp, err1 := http.Get(url)
if err1 != nil {
err = err1
return
} defer resp.Body.Close() //读取网页body内容
buf := make([]byte, 1024*4)
for {
n, _ := resp.Body.Read(buf)
if n == 0 { //读取结束，或者，出问题
//fmt.Println("resp.Body.Read err = ", err)
break
} result += string(buf[:n])
} return
} func DoWork(start, end int) {
fmt.Printf("正在爬取 %d 到 %d 的页面\n", start, end) //明确目标 (要知道你准备在哪个范围或者网站去搜索)
for i := start; i <= end; i++ {
url := "http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=" + strconv.Itoa((i-1)*50)
fmt.Println("url = ", url) //2) 爬 (将所有的网站的内容全部爬下来)
result, err := HttpGet(url)
if err != nil {
fmt.Println("HttpGet err = ", err)
continue
} //把内容写入到文件
fileName := strconv.Itoa(i) + ".html"
f, err1 := os.Create(fileName)
if err1 != nil {
fmt.Println("os.Create err1 = ", err1)
continue
} f.WriteString(result) //写内容 f.Close() //关闭文件
} } func main() {
var start, end int
fmt.Printf("请输入起始页( >= 1) :")
fmt.Scan(&start)
fmt.Printf("请输入终止页( >= 起始页) :")
fmt.Scan(&end) DoWork(start, end)
}
执行结果：
请输入起始页( >= 1) :1 //输入起始页
请输入终止页( >= 起始页) :10 //输入终止页
正在爬取 1 到 10 的页面
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=0
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=50
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=100
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=150
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=200
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=250
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=300
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=350
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=400
url = http://tieba.baidu.com/f?kw=%E7%BB%9D%E5%9C%B0%E6%B1%82%E7%94%9F&ie=utf-8&pn=450
