Golang协程与Python协程速度比较

本实验通过抓取50页诗词并做对每一页里面的a标签对应的html页面（每页40个a标签）进行抓取，然后对html做简单解析，总共就是请求50+50*40 = 2050个页面，并解析这些页面的html内容。

1.Python 速度

31.947秒

源码：

from bs4 import BeautifulSoup
import time
import aiohttp
import asyncio

async def do_task(domain, pageUrl):
    async with aiohttp.ClientSession() as session:
        async with session.request('GET', pageUrl) as resp:
            if resp.status != 200:
                raise Exception('http error, url:{} code:{}'.format(pageUrl, resp.status))
            html = await resp.read()  # 可直接获取bytes
    soup = BeautifulSoup(html, 'html.parser')
    for h in soup.select('h3>a'):
        url = ''.join([domain, h.get('href')])
        async with aiohttp.ClientSession() as session:
            async with session.request('GET', url) as resp:
                if resp.status != 200:
                    raise Exception('http error, url:{} code:{}'.format(pageUrl, resp.status))
                html = await resp.read()  # 可直接获取bytes
        print('url:{} title:{}'.format(url, parse_text(html)))


def parse_text(html):
    soup = BeautifulSoup(html, 'html.parser')
    return str(soup.select('.shici-title')[0].get_text())


def main():
    domain = 'http://www.shicimingju.com'
    urlTemplate = domain + '/chaxun/zuozhe/9_{0}.html'
    pageNum = 50  # 读取50页诗词进行测试
    loop = asyncio.get_event_loop()  # 获取事件循环
    tasks = []
    for num in range(pageNum + 1):
        tasks.append(do_task(domain, urlTemplate.format(num + 1)))
    loop.run_until_complete(asyncio.wait(tasks))  # 协程
    loop.close()


if __name__ == '__main__':
    start = time.time()
    main()  # 调用方
    print('总耗时：%.3f秒' % float(time.time() - start))

2. Golang 速度

15.366秒

源码：

package main

import (
    "fmt"
    "github.com/PuerkitoBio/goquery"
    "strconv"
    "strings"
    "sync"
    "time"
)

func do_task(url string, domain string) {
    p, err := goquery.NewDocument(url)
    if err != nil {
        panic(err)
    } else {
        p.Find("h3").Find("a").Each(func(i int, selection *goquery.Selection) {
            href, _ := selection.Attr("href")
            link := domain + href
            h, err := goquery.NewDocument(link)
            if err != nil {
                panic(err)
            } else {
                title := h.Find(".shici-title").Text()
                fmt.Printf("url:%s title:%s \n", link, title)
            }
        })
    }
    wg.Done()
}

var wg sync.WaitGroup

func main()  {
    start := time.Now().UnixNano()
    domain := "http://www.shicimingju.com"
    urlTemplate := domain + "/chaxun/zuozhe/9_{:num}.html"
    pageNum := 50
    wg.Add(50)
    for page := 1; page <= pageNum; page++ {
        url := strings.Replace(urlTemplate, "{:num}", strconv.Itoa(page), -1)
        go do_task(url, domain)
    }
    wg.Wait()
    end := time.Now().UnixNano()
    fmt.Printf("总耗时：%.3f秒 \n", float32(end - start)/1000000000)
}

3.结论

Golang的性能妥妥地要比Python，PHP好，毕竟是为并发而生的语言。