python实训day4

今天是python实训的第四天，今天教的主要是一些使用的技能。

一、python爬虫：

1.爬取梨视频页面全部视频：

 
'''
爬取梨视频:
请求url:
    https://www.pearvideo.com/
     
请求方式:
    GET
     
请求头:
    user-agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36
'''
 
# import requests
# import re  # 正则模块
#
# # 1、对梨视频详情页发送请求，获取响应数据
# response = requests.get(url='https://www.pearvideo.com/')
# print(response.status_code)
# print(response.text)
#
# # re.findall('正则匹配规则', '解析文本', "正则模式")
# # re.S: 全局模式 （对整个文本行进匹配）
# # .指的是当前位置
# # *指的是查找所有
# '''
# <a href="video_1543373"
# <a href="video_(.*?)"  # 提取1543373
# '''
#
# # 2、获取主页视频详情页ID
# res = re.findall('<a href="video_(.*?)"', response.text, re.S)
# print(res)
#
#
# for m_id in res:
#     # 拼接详情页url
#     detail_url = 'https://www.pearvideo.com/video_' + m_id
#     print(detail_url)
 
 
 
import requests
import re  # 正则模块
# uuid.uuid4()  可以根据时间戳生成一段世界上唯一的随机字符串
import uuid
 
# 爬虫三部曲
 
# 1、发送请求
def get_page(url):
    response = requests.get(url)
    return response
 
# 2、解析数据
# 解析主页获取视频详情页ID
def parse_index(text):
    res = re.findall('<a href="video_(.*?)"', text, re.S)
    # print(res)
 
    detail_url_list = []
    for m_id in res:
        # 拼接详情页url
        detail_url = 'https://www.pearvideo.com/video_' + m_id
        # print(detail_url)
        detail_url_list.append(detail_url)
 
    # print(detail_url_list)
 
    return detail_url_list
 
# 解析详情页获取视频url
def parse_detail(text):
    ''''''
    '''
        (.*?)： 提取括号的内容
        .*?： 直接匹配
        <video webkit-playsinline="" playsinline="" x-webkit-airplay="" autoplay="autoplay" src="https://video.pearvideo.com/mp4/adshort/20190613/cont-1566073-14015522_adpkg-ad_hd.mp4" style=" 100%; height: 100%;"></video>
         
    正则: <video.*?src="(.*?)"
     
    # 以上是分析过程，不需要写
     
    正则: srcUrl="(.*?)"
    '''
    movie_url = re.findall('srcUrl="(.*?)"', text, re.S)[0]
    return movie_url
 
 
# 3、保存数据
def save_movie(movie_url):
    response = requests.get(movie_url)
    # 把视频写到本地
    with open(f'{uuid.uuid4()}.mp4', 'wb') as f:
        f.write(response.content)
        f.flush()
 
if __name__ == '__main__':  # main + 回车键
 
    # 1、对主页发送请求
    index_res = get_page(url='https://www.pearvideo.com/')
 
    # 2、对主页进行解析、获取详情页id
    detail_url_list = parse_index(index_res.text)
    # print(detail_url_list)
 
    # 3、对每个详情页url发送请求
    for detail_url in detail_url_list:
        detail_res = get_page(url=detail_url)
        print(detail_res.text)
 
        # 4、解析详情页获取视频url
        movie_url = parse_detail(detail_res.text)
        print(movie_url)
 
        # 5、保存视频
        save_movie(movie_url)

　　2.以上内容更高性能爬取：

import requests
import re  # 正则模块
# uuid.uuid4()  可以根据时间戳生成一段世界上唯一的随机字符串
import uuid
# 导入线程池模块
from concurrent.futures import ThreadPoolExecutor
# 线程池限制50个线程
pool = ThreadPoolExecutor(50)
 
# 爬虫三部曲
 
# 1、发送请求
def get_page(url):
    print(f'开始异步任务: {url}')
    response = requests.get(url)
    return response
 
 
# 2、解析数据
# 解析主页获取视频详情页ID
def parse_index(res):
 
    response = res.result()
    # 提取出主页所有ID
    id_list = re.findall('<a href="video_(.*?)"', response.text, re.S)
    # print(res)
 
    # 循环id列表
    for m_id in id_list:
        # 拼接详情页url
        detail_url = 'https://www.pearvideo.com/video_' + m_id
        # print(detail_url)
        # 把详情页url提交给get_page函数
        pool.submit(get_page, detail_url).add_done_callback(parse_detail)
 
 
# 解析详情页获取视频url
def parse_detail(res):
    response = res.result()
    movie_url = re.findall('srcUrl="(.*?)"', response.text, re.S)[0]
    # 异步提交把视频url传给get_page函数,把返回的结果传给save_movie
    pool.submit(get_page, movie_url).add_done_callback(save_movie)
 
 
# 3、保存数据
def save_movie(res):
 
    movie_res = res.result()
 
    # 把视频写到本地
    with open(f'{uuid.uuid4()}.mp4', 'wb') as f:
        f.write(movie_res.content)
        print(f'视频下载结束: {movie_res.url}')
        f.flush()
 
 
if __name__ == '__main__':  # main + 回车键
 
    # 一 往get_page发送异步请求，把结果交给parse_index函数
    url = 'https://www.pearvideo.com/'
    pool.submit(get_page, url).add_done_callback(parse_index)

　　3.requests的详细使用：

GET请求讲解
'''
'''
User-Agent
# 访问知乎发现
请求url:
    https://www.zhihu.com/explore
     
请求方式:
    GET
     
请求头:
    user-agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36
     
    cookies
'''
 
# 访问知乎
# import requests
# response = requests.get(url='https://www.zhihu.com/explore')
# print(response.status_code)  # 400
# print(response.text)  # 返回错误页面
 
 
# 携带请求头参数访问知乎:
import requests
 
# 请求头字典
# headers = {
#     'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36'
# }
# 在get请求内，添加user-agent
# response = requests.get(url='https://www.zhihu.com/explore', headers=headers)
# print(response.status_code)  # 200
# # print(response.text)
# with open('zhihu.html', 'w', encoding='utf-8') as f:
#     f.write(response.text)
 
 
'''
params请求参数
访问百度搜查安徽工程大学url
https://www.baidu.com/s?wd=安徽工程大学&pn=10
https://www.baidu.com/s?wd=安徽工程大学&pn=20
 
# '''
from urllib.parse import urlencode
# url = 'https://www.baidu.com/s?wd=%E8%94%A1%E5%BE%90%E5%9D%A4'
# url = 'https://www.baidu.com/s?' + urlencode({"wd": "蔡徐坤"})
url = 'https://www.baidu.com/s?'
headers = {
    'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36'
}
# print(url)
# 在get方法中添加params参数
# response = requests.get(url, headers=headers, params={"wd": "安徽工程大学"})
response = requests.get(url, headers=headers, params={"wd": "安徽工程大学", "pn": "20"})
# print(response.text)
with open('gongcheng2.html', 'w', encoding='utf-8') as f:
    f.write(response.text)
 
 
'''
携带cookies
携带登录cookies破解github登录验证
 
请求url:
    https://github.com/settings/emails
     
请求方式:
    GET
     
请求头:
    User-Agen
     
    Cookie: has_recent_activity=1; _ga=GA1.2.1416117396.1560496852; _gat=1; tz=Asia%2FShanghai; _octo=GH1.1.1728573677.1560496856; _device_id=1cb66c9a9599576a3b46df2455810999; user_session=1V8n9QfKpbgB-DhS4A7l3Tb3jryARZZ02NDdut3J2hy-8scm; __Host-user_session_same_site=1V8n9QfKpbgB-DhS4A7l3Tb3jryARZZ02NDdut3J2hy-8scm; logged_in=yes; dotcom_user=TankJam; _gh_sess=ZS83eUYyVkpCWUZab21lN29aRHJTUzgvWjRjc2NCL1ZaMHRsdGdJeVFQM20zRDdPblJ1cnZPRFJjclZKNkcrNXVKbTRmZ3pzZzRxRFExcUozQWV4ZG9kOUQzZzMwMzA2RGx5V2dSaTMwaEZ2ZDlHQ0NzTTBtdGtlT2tVajg0c0hYRk5IOU5FelYxanY4T1UvVS9uV0YzWmF0a083MVVYVGlOSy9Edkt0aXhQTmpYRnVqdFAwSFZHVHZQL0ZyQyt0ZjROajZBclY4WmlGQnNBNTJpeEttb3RjVG1mM0JESFhJRXF5M2IwSlpHb1Mzekc5M0d3OFVIdGpJaHg3azk2aStEcUhPaGpEd2RyMDN3K2pETmZQQ1FtNGNzYnVNckR4aWtibkxBRC8vaGM9LS1zTXlDSmFnQkFkWjFjanJxNlhCdnRRPT0%3D--04f6f3172b5d01244670fc8980c2591d83864f60
     
'''
import requests
 
# 请求url
url = 'https://github.com/settings/emails'
 
# 请求头
headers = {
    'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36',
    # 在请求头中拼接cookies
    # 'Cookie': 'has_recent_activity=1; _ga=GA1.2.1416117396.1560496852; _gat=1; tz=Asia%2FShanghai; _octo=GH1.1.1728573677.1560496856; _device_id=1cb66c9a9599576a3b46df2455810999; user_session=1V8n9QfKpbgB-DhS4A7l3Tb3jryARZZ02NDdut3J2hy-8scm; __Host-user_session_same_site=1V8n9QfKpbgB-DhS4A7l3Tb3jryARZZ02NDdut3J2hy-8scm; logged_in=yes; dotcom_user=TankJam; _gh_sess=ZS83eUYyVkpCWUZab21lN29aRHJTUzgvWjRjc2NCL1ZaMHRsdGdJeVFQM20zRDdPblJ1cnZPRFJjclZKNkcrNXVKbTRmZ3pzZzRxRFExcUozQWV4ZG9kOUQzZzMwMzA2RGx5V2dSaTMwaEZ2ZDlHQ0NzTTBtdGtlT2tVajg0c0hYRk5IOU5FelYxanY4T1UvVS9uV0YzWmF0a083MVVYVGlOSy9Edkt0aXhQTmpYRnVqdFAwSFZHVHZQL0ZyQyt0ZjROajZBclY4WmlGQnNBNTJpeEttb3RjVG1mM0JESFhJRXF5M2IwSlpHb1Mzekc5M0d3OFVIdGpJaHg3azk2aStEcUhPaGpEd2RyMDN3K2pETmZQQ1FtNGNzYnVNckR4aWtibkxBRC8vaGM9LS1zTXlDSmFnQkFkWjFjanJxNlhCdnRRPT0%3D--04f6f3172b5d01244670fc8980c2591d83864f60'
}
# github_res = requests.get(url, headers=headers)
 
import requests
cookies = {
    'Cookie': 'has_recent_activity=1; _ga=GA1.2.1416117396.1560496852; _gat=1; tz=Asia%2FShanghai; _octo=GH1.1.1728573677.1560496856; _device_id=1cb66c9a9599576a3b46df2455810999; user_session=1V8n9QfKpbgB-DhS4A7l3Tb3jryARZZ02NDdut3J2hy-8scm; __Host-user_session_same_site=1V8n9QfKpbgB-DhS4A7l3Tb3jryARZZ02NDdut3J2hy-8scm; logged_in=yes; dotcom_user=TankJam; _gh_sess=ZS83eUYyVkpCWUZab21lN29aRHJTUzgvWjRjc2NCL1ZaMHRsdGdJeVFQM20zRDdPblJ1cnZPRFJjclZKNkcrNXVKbTRmZ3pzZzRxRFExcUozQWV4ZG9kOUQzZzMwMzA2RGx5V2dSaTMwaEZ2ZDlHQ0NzTTBtdGtlT2tVajg0c0hYRk5IOU5FelYxanY4T1UvVS9uV0YzWmF0a083MVVYVGlOSy9Edkt0aXhQTmpYRnVqdFAwSFZHVHZQL0ZyQyt0ZjROajZBclY4WmlGQnNBNTJpeEttb3RjVG1mM0JESFhJRXF5M2IwSlpHb1Mzekc5M0d3OFVIdGpJaHg3azk2aStEcUhPaGpEd2RyMDN3K2pETmZQQ1FtNGNzYnVNckR4aWtibkxBRC8vaGM9LS1zTXlDSmFnQkFkWjFjanJxNlhCdnRRPT0%3D--04f6f3172b5d01244670fc8980c2591d83864f60'
}
 
github_res = requests.get(url, headers=headers, cookies=cookies)
 
print('15622792660' in github_res.text)

　　4.实例：爬取豆瓣top250电影信息：

''''''
'''
主页:
    https://movie.douban.com/top250
    GET
    User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36
     
re正则:
    # 电影详情页url、图片链接、电影名称、电影评分、评价人数
    <div class="item">.*?href="(.*?)">.*?src="(.*?)".*?<span class="title">(.*?)</span>.*?<span class="rating_num".*?>(.*?)</span>.*?<span>(.*?)人评价
'''
import requests
import re
url = 'https://movie.douban.com/top250'
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.146 Safari/537.36'
}
# 1、往豆瓣TOP250发送请求获取响应数据
response = requests.get(url, headers=headers)
 
# print(response.text)
 
# 2、通过正则解析提取数据
# 电影详情页url、图片链接、电影名称、电影评分、评价人数
movie_content_list = re.findall(
    # 正则规则
    '<div class="item">.*?href="(.*?)">.*?src="(.*?)".*?<span class="title">(.*?)</span>.*?<span class="rating_num".*?>(.*?)</span>.*?<span>(.*?)人评价',
 
    # 解析文本
    response.text,
 
    # 匹配模式
    re.S)
 
for movie_content in movie_content_list:
    # 解压赋值每一部电影
    detail_url, movie_jpg, name, point, num = movie_content
    data = f'电影名称:{name},   详情页url:{detail_url}, 图片url:{movie_jpg}, 评分: {point}, 评价人数: {num} 
'
    print(data)
 
    # 3、保存数据，把电影信息写入文件中
    with open('douban.txt', 'a', encoding='utf-8') as f:
        f.write(data)