爬虫基本原理

　　一.使用requests 模块 是基于urllib库 

　　1.requests.get() 的请求

import requests

# 使用requests 模块 是基于urllib
#  urllib python 内置的模块 也是没扣你发送http请求的库
# 模拟http请求， get post put delete

# 1 get 请求
# res = requests.get('https://www.baidu.com')
# # print(res)  # <Response [200]>
#
# # 注意编码的问题
# res.encoding = 'utf-8'
# print(res.text)  # 百度首页的内容  》》》 响应的内容
#
# with open('a.html', 'w')as f:  # 百度首页登录的页面
#
#     f.write(res.text)

　

　　2.requests.get() 的参数和编码的问题   报错‘gbk’  》》》

　　　　1.'gbk' 编码格式的问题

# 1 get 请求
# res = requests.get('https://www.baidu.com')
# # print(res)  # <Response [200]>
#
# # 注意编码的问题
# res.encoding = 'utf-8'

　　

　　2.必传参数

# 2. get 请求携带参数
# User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36
# request.get()的方法的参数

# def get(url, params=None, **kwargs):
#     r"""Sends a GET request.
# https://www.baidu.com/s?wd=%E6%9C%80%E7%BE%8E%E9%A3%8E%E6%99%AF%E5%9B%BE
# res = requests.get('https://www.baidu.com/s',
#                    params={"wd": '最美风景图'},
#                     # 请求头的信息
#                    headers={'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36'})
#
# res.encoding = 'utf-8'
# # print(res.text)  # 请求的内容
# #  <div class="timeout-title">网络不给力，请稍后重试</div>
# with open('a.html', 'w')as f:
#     f.write(res.text)
#   <div class="timeout-title">网络不给力，请稍后重试</div>  无法访问的这样

　　3.模拟用户登录的实列 》》 华华手机
　　　参数准备

  （1）headers 中 User_Agent  Referer  cookie = res.cookies.get()

　　　格式案列：

# >>>> 模拟登录网站  User_Agent: Referer cookie
headers = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36",

    'Referer': 'http://www.aa7a.cn/user.php?&ref=http%3A%2F%2Fwww.aa7a.cn%2Findex.php'}

res = requests.post('http://www.aa7a.cn/user.php',
                    headers=headers,
                    data={
                        'username': '1024359512@qq.com ',
                        "password": 'mo1234',
                        'captcha': 'mkab',
                        'remember': 1,
                        'ref': 'http://www.aa7a.cn/index.php',
                        'act': 'act_login'
                    }
                    )

# 如果登录成功，cookie存在在于对象 中
cookie = res.cookies.get_dict()  # 生成cookie
# 向首页发送get请求
res = requests.get('http://www.aa7a.cn/user.php?&ref=http%3A%2F%2Fwww.aa7a.cn%2Fuser.php%3Fact%3Dlogout',
                   headers=headers,
                   cookies=cookie)

# 判断
if '1024359512@qq.com' in res.text:
    print('登录成功')
else:
    print('没有登录')

"""
""

username: koko
password: mo123
captcha: nkab
remember: 1
ref: http://www.aa7a.cn/
act: act_login
"""

　　3.requests.get() 爬取电影

# 爬取视频
# Request URL: https://www.pearvideo.com/category_loading.jsp?reqType=5&categoryId=1&start=12&mrd=0.025906198752709164&filterIds=1625830,1625746,1625846,1626267,1626185,1625876,1626253,1626235,1626236,1626232,1626243,1626215,1626218,1626241,1625836
# Request URL: https://www.pearvideo.com/category_loading.jsp?reqType=5&categoryId=1&start=0  #从第零条开始
import re
res = requests.get('https://www.pearvideo.com/category_loading.jsp?reqType=5&categoryId=1&start=0')
reg_text = '<a href="(.*?)" class="vervideo-lilink actplay">'
obj = re.findall(reg_text, res.text)
print(obj)
for url in obj:
    url = 'https://www.pearvideo.com/'+url
    res1 = requests.get(url)
    obj1 = re.findall('srcUrl="(.*?)"', res1.text)
    # ['https://video.pearvideo.com/mp4/adshort/20191125/cont-1626267-14630490_adpkg-ad_hd.mp4'] 666
    print(obj1[0],111)
    # https://video.pearvideo.com/mp4/adshort/20191125/cont-1626267-14630490_adpkg-ad_hd.mp4
    name = obj1[0].rsplit('/',1)[1]  # 一左边的第一'/' 进行切分 1 >>切分一次[1]下标1 作为电影名字
    print(name)  # cont-1626267-14630490_adpkg-ad_hd.mp4  电影名
    res2 = requests.get(obj1[0])
    with open(name, 'wb')as f:
        for line in res2.iter_content():
            f.write(line)

 　　url_text 

·　　后端代码

 　　4. 明天。。。。