爬虫（六）：案例：爬取扇贝英语单词+爬取网易云所有歌手+爬取酷狗音乐所有歌手

爬取网站的流程

• 确定网站的哪个url是数据的来源
• 简要分析一下网站结构，查看数据存放在哪里
• 查看是否有分页，并解决分页的问题
• 发送请求，查看response.text是否有我们所需要的数据
• 筛选数据

案例一：使用xpath爬取扇贝英语单词

需求：爬取三页单词

import json

import requests
from lxml import etree
base_url = 'https://www.shanbay.com/wordlist/110521/232414/?page=%s'
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Safari/537.36'
}


def get_text(value):
    if value:
        return value[0]
    return ''


word_list = []
for i in range(1, 4):
    # 发送请求
    response = requests.get(base_url % i, headers=headers)
    # print(response.text)
    html = etree.HTML(response.text)
    tr_list = html.xpath('//tbody/tr')
    # print(tr_list)
    for tr in tr_list:
        item = {}#构造单词列表
        en = get_text(tr.xpath('.//td[@class="span2"]/strong/text()'))
        tra = get_text(tr.xpath('.//td[@class="span10"]/text()'))
        print(en, tra)
        if en:
            item[en] = tra
            word_list.append(item)

面向对象：

import requests
from lxml import etree


class Shanbei(object):
    def __init__(self):
        self.base_url = 'https://www.shanbay.com/wordlist/110521/232414/?page=%s'
        self.headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Safari/537.36'
        }
        self.word_list = []
        self.parse()

    def get_text(self, value):
        # 防止为空报错
        if value:
            return value[0]
        return ''

    def parse(self):
        for i in range(1, 4):
            # 发送请求
            response = requests.get(self.base_url % i, headers=self.headers)
            # print(response.text)
            html = etree.HTML(response.text)
            tr_list = html.xpath('//tbody/tr')
            # print(tr_list)
            for tr in tr_list:
                item = {}  # 构造单词列表
                en = self.get_text(tr.xpath('.//td[@class="span2"]/strong/text()'))
                tra = self.get_text(tr.xpath('.//td[@class="span10"]/text()'))
                print(en, tra)
                if en:
                    item[en] = tra
                    self.word_list.append(item)


shanbei = Shanbei()

案例二：爬取网易云音乐的所有歌手名字

import requests,json
from lxml import etree

url = 'https://music.163.com/discover/artist'
singer_infos = []


# ---------------通过url获取该页面的内容，返回xpath对象
def get_xpath(url):
    headers = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Safari/537.36'
    }
    response = requests.get(url, headers=headers)
    return etree.HTML(response.text)


# --------------通过get_xpath爬取到页面后，我们获取华宇，华宇男等分类
def parse():
    html = get_xpath(url)
    fenlei_url_list = html.xpath('//ul[@class="nav f-cb"]/li/a/@href')  # 获取华宇等分类的url
    # print(fenlei_url_list)
    # --------将热门和推荐两栏去掉筛选
    new_list = [i for i in fenlei_url_list if 'id' in i]
    for i in new_list:
        fenlei_url = 'https://music.163.com' + i
        parse_fenlei(fenlei_url)
        # print(fenlei_url)


# -------------通过传入的分类url，获取A,B，C页面内容
def parse_fenlei(url):
    html = get_xpath(url)
    # 获得字母排序，每个字母的链接
    zimu_url_list = html.xpath('//ul[@id="initial-selector"]/li[position()>1]/a/@href')
    for i in zimu_url_list:
        zimu_url = 'https://music.163.com' + i
        parse_singer(zimu_url)


# ---------------------传入获得的字母链接，开始爬取歌手内容
def parse_singer(url):
    html = get_xpath(url)
    item = {}
    singer_names = html.xpath('//ul[@id="m-artist-box"]/li/p/a/text()')
    # --详情页看到页面结构会有两个a标签，所以取第一个
    singer_href = html.xpath('//ul[@id="m-artist-box"]/li/p/a[1]/@href')
    # print(singer_names,singer_href)
    for i, name in enumerate(singer_names):
        item['歌手名'] = name
        item['音乐链接'] = 'https://music.163.com' + singer_href[i].strip()
        # 获取歌手详情页的链接
        url = item['音乐链接'].replace(r'?id', '/desc?id')
        # print(url)
        parse_detail(url, item)

        print(item)


# ---------获取详情页url和存着歌手名字和音乐列表的字典，在字典中添加详情页数据
def parse_detail(url, item):
    html = get_xpath(url)
    desc_list = html.xpath('//div[@class="n-artdesc"]/p/text()')
    item['歌手信息'] = desc_list
    singer_infos.append(item)
    write_singer(item)


# ----------------将数据字典写入歌手文件
def write_singer(item):
    with open('singer.json', 'a+', encoding='utf-8') as file:
        json.dump(item,file)


if __name__ == '__main__':
    parse()

面向对象

import json, requests
from lxml import etree


class Wangyiyun(object):
    def __init__(self):
        self.url = 'https://music.163.com/discover/artist'
        self.singer_infos = []
        self.headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Safari/537.36'
        }
        self.parse()

    # ---------------通过url获取该页面的内容，返回xpath对象
    def get_xpath(self, url):
        response = requests.get(url, headers=self.headers)
        return etree.HTML(response.text)

    # --------------通过get_xpath爬取到页面后，我们获取华宇，华宇男等分类
    def parse(self):
        html = self.get_xpath(self.url)
        fenlei_url_list = html.xpath('//ul[@class="nav f-cb"]/li/a/@href')  # 获取华宇等分类的url
        # print(fenlei_url_list)
        # --------将热门和推荐两栏去掉筛选
        new_list = [i for i in fenlei_url_list if 'id' in i]
        for i in new_list:
            fenlei_url = 'https://music.163.com' + i
            self.parse_fenlei(fenlei_url)
            # print(fenlei_url)

    # -------------通过传入的分类url，获取A,B，C页面内容
    def parse_fenlei(self, url):
        html = self.get_xpath(url)
        # 获得字母排序，每个字母的链接
        zimu_url_list = html.xpath('//ul[@id="initial-selector"]/li[position()>1]/a/@href')
        for i in zimu_url_list:
            zimu_url = 'https://music.163.com' + i
            self.parse_singer(zimu_url)

    # ---------------------传入获得的字母链接，开始爬取歌手内容
    def parse_singer(self, url):
        html = self.get_xpath(url)
        item = {}
        singer_names = html.xpath('//ul[@id="m-artist-box"]/li/p/a/text()')
        # --详情页看到页面结构会有两个a标签，所以取第一个
        singer_href = html.xpath('//ul[@id="m-artist-box"]/li/p/a[1]/@href')
        # print(singer_names,singer_href)
        for i, name in enumerate(singer_names):
            item['歌手名'] = name
            item['音乐链接'] = 'https://music.163.com' + singer_href[i].strip()
            # 获取歌手详情页的链接
            url = item['音乐链接'].replace(r'?id', '/desc?id')
            # print(url)
            self.parse_detail(url, item)

            print(item)

    # ---------获取详情页url和存着歌手名字和音乐列表的字典，在字典中添加详情页数据
    def parse_detail(self, url, item):
        html = self.get_xpath(url)
        desc_list = html.xpath('//div[@class="n-artdesc"]/p/text()')[0]
        item['歌手信息'] = desc_list
        self.singer_infos.append(item)
        self.write_singer(item)

    # ----------------将数据字典写入歌手文件
    def write_singer(self, item):
        with open('sing.json', 'a+', encoding='utf-8') as file:
            json.dump(item, file)


music = Wangyiyun()

案例三：爬取酷狗音乐的歌手和歌单

需求：爬取酷狗音乐的歌手和歌单和歌手简介

import json, requests
from lxml import etree

base_url = 'https://www.kugou.com/yy/singer/index/%s-%s-1.html'
# ---------------通过url获取该页面的内容，返回xpath对象
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Safari/537.36'
}


# ---------------通过url获取该页面的内容，返回xpath对象
def get_xpath(url, headers):
    try:
        response = requests.get(url, headers=headers)
        return etree.HTML(response.text)
    except Exception:
        print(url, '该页面没有相应！')
        return ''


# --------------------通过歌手详情页获取歌手简介
def parse_info(url):
    html = get_xpath(url, headers)
    info = html.xpath('//div[@class="intro"]/p/text()')
    return info


# --------------------------写入方法
def write_json(value):
    with open('kugou.json', 'a+', encoding='utf-8') as file:
        json.dump(value, file)


# -----------------------------用ASCII码值来变换abcd...
for j in range(97, 124):
    # 小写字母为97-122，当等于123的时候我们按歌手名单的其他算，路由为null
    if j