day_3

Today's study is mainly reptiles principles and Requests library request

a reptile principle
    1. What is the Internet? 
It refers to a stack of a network device, to the computer station to the Internet together with a called Internet.

2. The purpose of the establishment of the Internet?
The purpose is to establish the Internet transfer and data sharing data.

3. What is the data?
For example ... Taobao, Jingdong product information such as
number of securities investment information East Fortune, snowball network ...
the chain of home, such as availability of information freely ....
12306 ticket information ...

4. The whole process of the Internet:
- ordinary users:
open browser -> sending a request to a target site -> the fetch response data -> renderer in the browser

- crawlers:
analog browser -> sending a request to a target site -> the fetch response data - -> extract valuable data -> persisted to the data


5. What is the browser sends a request?
request http protocol.

- Client:
the browser is a software -> Client IP and port


- server
https://www.jd.com/
www.jd.com (Jingdong domain name) -> DNS parsing -> IP server and Jingdong port

Client ip and port ------> IP and port to send the request to the server can establish a link to obtain the corresponding data.


6. The crawler whole process
- the transmission request (request requires libraries: Requests database request, requesting the Selenium library)
- fetch response data (as long as the transmission request to the server, the request returns response data)
- parses and extracts data (requires parsing library : Re, BeautifulSoup4, the Xpath ...)
- saved locally (file processing, database, MongoDB repository)


two requests requests library

1. installation and use
- open cmd
- input: requests the install PIP3

2. crawling video


3. grip packet analysis
open developer mode browser (check) ----> select the network
to find the page suffix xxx.html access (response text)

1) the request url (website address access)
2) request method:
GET:
direct send request the data
https://www.cnblogs.com/kermitjam/articles/9692597.html

the POST:
Need to carry the user information transmission request to the target address
https://www.cnblogs.com/login

. 3) Response Status Code:
2xx: Success
3xx: Redirection
4xx: resource not found
5xx: Server Error

4) the request header:
the User -Agent: user agent (proved to be a request by computer equipment and sent by the browser)
Cookies: real user login information (user prove your target site)
Referer: url on the first visit (to prove that you are jumping from target sites on the web )

5) request body:
POST request will have the request body.
The Data Form
{
'the User': 'Tank',
'pwd': '123'
}


four crawling IMDb
: starting from the current position
*: Find all
:? Find the first not to look

. * ?: non-greedy match
*: Greed match

: extract data in brackets (. *?)

Movie rankings, movies url, film name, director - starring - the type of movie scores, number of reviews, film synopsis
<div class = "item"> *.? <EM class = ""> (. *?) </ EM>
. *? <a href="(.*?)">. *? <span class = "title"> (. *?) </ span >
* director:.? (.? *).?.? (.? *) </ the p-> * <span class = "rating_num" *> </ span>
.? (.? *) * <span> people evaluation </ span>. *? <span class = "INQ"> (. *?) </ span>



<div class = "Item">
<div class = "PIC">
<EM class = ""> 226 < / EM>
<a href="https://movie.douban.com/subject/1300374/">
<IMG width = "100" Alt = "The green Mile" src = "https: //img3.doubanio.com/view/photo/s_ratio_poster/public/p767586451.webp" class="">
</a>
</div>
<div class="info">
<div class="hd">
href="https://movie.douban.com/subject/1300374/" class=""> <a
<span class = "title"> Green Mile </ span>
<span class = "title"> & nbsp; / & nbsp; of The green mile </ span>
<span class = "OTHER"> & nbsp; / & nbsp; The green mile (units) / green mile </ span>
</a>


<span class = "playable"> [playable ] </ span>
</ div>
<div class = "bd">
<the p-class = "">
director: Frank Darabont & nbsp; & nbsp ; & nbsp; starring: Tom Hanks Tom Hanks / David Morse David M <br> ...
1999 & nbsp; / & nbsp; USA & nbsp; / & nbsp;Fantasy Crime Mystery Drama
</ P>


<div class = "Star">
<span class = "T-rating45"> </ span>
<span class="rating_num" property="v:average">8.7</span>
<span property="v:best" content="10.0"></span>
<span>141370人评价</span>
</div>

<p class="quote">
<span class="inq">天使暂时离开。</span>
</p>
</div>
</div>
</div>

import requests # import request requests Library # Baidu home page to send a request to obtain the response object response
= requests.get(url='https://www.baidu.com/') # Set the character encoding to UTF - . 8 response.encoding = ' UTF-. 8 ' # Print the response text print(response.text) # The text is written in response to local with open('baidu.html', 'w', encoding='utf-8') as f: f.write(response.text) '' '' '' '' ' Video options: 1 . Pears video ' '' # Import Requests # ## to the source address of the video transmission request # response = requests.get( # 'https://video.pearvideo.com/mp4/adshort/20190625/cont-1570302-14057031_adpkg-ad_hd.mp4') # # # Print binary stream, such as pictures, video and other data # print(response.content) # # # Save the video to your local # with open('视频.mp4', 'wb') as f: # f.write(response.content) '' ' 1 , first sends a request to the Video Home pear https://www.pearvideo.com/ Id get resolved for all videos: video_1570302 re.findall() 2 , access to video details page url: Thrilling ! Man robbed on the subway slip, go on foot HTTPS: // www.pearvideo.com/video_1570302 Secret Karez https://www.pearvideo.com/video_1570107 ''' import requests import re # regularization, for parsing text data # 1 , first send a request to the pear Video Home response = requests.get('https://www.pearvideo.com/') # print(response.text) # Re regular matches to get all video id Parameter # 1: Regular matching rules Parameter # 2: parse text Parameter # 3: Match mode res_list = re.findall('<a href="video_(.*?)"', response.text, re.S) # print(res_list) # Stitching each video detail page url for v_id in res_list: detail_url = 'https://www.pearvideo.com/video_' + v_id # print(detail_url) # Sending a request to obtain the video source url for each video detail page response = requests.get(url=detail_url) # print(response.text) # Parse and extract details page video url # Video url video_url = re.findall('srcUrl="(.*?)"', response.text, re.S)[0] print(video_url) # Name video video_name = re.findall( '<h1 class="video-tt">(.*?)</h1>', response.text, re.S)[0] print(video_name) # Binary stream to acquire a video transmission request video url v_response = requests.get(video_url) with open('%s.mp4' % video_name, 'wb') as f: f.write(v_response.content) Print (video_name, ' video crawling completed ' ) '' '' '' '' ' video options: 1 . Pear Video ' '' # Import Requests # ## to the source address of the video transmission request # response = requests.get( # 'https://video.pearvideo.com/mp4/adshort/20190625/cont-1570302-14057031_adpkg-ad_hd.mp4') # # # Print binary stream, such as pictures, video and other data # print(response.content) # # # Save the video to your local # with open('视频.mp4', 'wb') as f: # f.write(response.content) '' ' 1 , first sends a request to the Video Home pear https://www.pearvideo.com/ Id get resolved for all videos: video_1570302 re.findall() 2 , access to video details page url: Thrilling ! Man robbed on the subway slip, go on foot HTTPS: // www.pearvideo.com/video_1570302 Secret Karez https://www.pearvideo.com/video_1570107 ''' import requests import re # regularization, for parsing text data # 1 , first send a request to the pear Video Home response = requests.get('https://www.pearvideo.com/') # print(response.text) # Re regular matches to get all video id Parameter # 1: Regular matching rules Parameter # 2: parse text Parameter # 3: Match mode res_list = re.findall('<a href="video_(.*?)"', response.text, re.S) # print(res_list) # Stitching each video detail page url for v_id in res_list: detail_url = 'https://www.pearvideo.com/video_' + v_id # print(detail_url) # Sending a request to obtain the video source url for each video detail page response = requests.get(url=detail_url) # print(response.text) # Parse and extract details page video url # Video url video_url = re.findall('srcUrl="(.*?)"', response.text, re.S)[0] print(video_url) # Name video video_name = re.findall( '<h1 class="video-tt">(.*?)</h1>', response.text, re.S)[0] print(video_name) # Binary stream to acquire a video transmission request video url v_response = requests.get(video_url) with open('%s.mp4' % video_name, 'wb') as f: f.write(v_response.content) Print (video_name, ' video crawling completed ' ) '''''' ''' https://movie.douban.com/top250?start=0&filter= https://movie.douban.com/top250?start=25&filter= https://movie.douban.com/top250?start=50&filter= A Request to Send 2 . Analytical data 3 . Save the data '' ' Import Requests import re # Reptile three-part song # 1 Request to Send def get_page(base_url): response = requests.get(base_url) return response # 2 . Parse text def parse_index(text): res = re.findall('<div class="item">.*?<em class="">(.*?)</em>.*?<a href="(.*?)">.*?<span class="title">(.*?)</span>.*?导演:(.*?)</p>.*?<span class="rating_num".*?>(.*?)</span>.*?<span>(.*?)人评价</span>.*?<span class="inq">(.*?)</span>', text, re.S) # print(res) return res # 3 Save data def save_data(data): with open('douban.txt', 'a', encoding='utf-8') as f: f.write(data) Main # + ENTER IF the __name__ == ' __main__ ' : A # = 10 # base_url = ' https://movie.douban.com/top250?start={}&filter= ' .format (a) num = 0 for line in range(10): base_url = f'https://movie.douban.com/top250?start={num}&filter=' num += 25 print(base_url) # 1 . Sends a request, call the function response = get_page(base_url) # 2 . Parse text movie_list = parse_index(response.text) # 3 Save data # Formatted data for movie in movie_list: # print(movie) # Decompression assignment Ranked # movie, movies url, film name, director - starring - the type of movie scores, number of reviews, film synopsis v_top, v_url, v_name, v_daoyan, v_point, v_num, v_desc = movie # v_top = movie[0] # v_url = movie[1] moive_content = F '' ' Movies Ranking: {v_top} Film url: {v_url} Movie Name: {v_name} Director Starring: {v_daoyan} Movie rating: {v_point} Number of Evaluation: {v_num} Movie Synopsis: {v_desc} \n ''' print(moive_content) # save data save_data(moive_content)

 

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Origin www.cnblogs.com/cxknmsl/p/11094217.html
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