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What needs to be installed for python crawler

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Release： 2019-12-28 11:47:03

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What needs to be installed for python crawler

80% of the world's crawlers are developed based on Python. Learning crawler skills can provide important data sources for subsequent big data analysis, mining, machine learning, etc.

Python crawler needs to install related libraries:

Libraries involved in python crawler:

Request library, parsing library, storage library, tool library

1. Request library: urllib/re/requests

(1) urllib/re is the library that comes with python by default and can be verified by the following command:

No error message is output, indicating that the environment is normal

(2) requests installation

2.1 Open CMD and enter

pip3 install requests

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2.2 Wait for installation and verify

(3) Selenium installation (drives the browser for website access behavior)

3.1 Open CMD and enter

pip3 install selenium

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3.2 Install chromedriver

Website: https://npm.taobao.org/

Decompress the downloaded compressed package and put the exe into D:\Python3.6.0\Scripts\

This path only needs to be in the PATH variable

3.3 After the installation is completed, verify

Press Enter and the chrome browser interface will pop up

3.4 Install other browsers

Interfaceless browser phantomjs

Download URL: http://phantomjs.org/

After downloading, unzip and put the entire directory Go to D:\Python3.6.0\Scripts\ and add the path to the bin directory to the PATH variable

Verification:

Open CMD

phantomjs
console.log(&#39;phantomjs&#39;)

CTRL+C

python
from selenium import webdriver
driver = webdriver.PhantomJS()
dirver.get(&#39;http://www.baidu.com&#39;)
driver.page_source

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2. Parsing library:

2.1 lxml (XPATH)

Open CMD

pip3 install lxml

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or download from https://pypi.python.org, for example, lxml-4.1.1-cp36- cp36m-win_amd64.whl (md5), first download the whl file

pip3 install 文件名.whl

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2.2 beautifulsoup

Open CMD, you need to install lxml

pip3 install beautifulsoup4

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Verification

python
from bs4 import BeautifulSoup
soup = BeautifulSoup(&#39;<html></html>&#39;,&#39;lxml&#39;)

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2.3 pyquery (similar to jquery syntax)

Open CMD

pip3 install pyquery

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Verify the installation results

python
from pyquery import PyQuery as pq
doc = pq(&#39;<html>hi</html>&#39;)
result = doc(&#39;html&#39;).text()
result

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3. Repository

3.1 pymysql (operating MySQL, relational database)

Installation:

pip3 install pymysql

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Test after installation:

3.2 pymongo (operating MongoDB, key-value)

Installation

pip3 install pymongo

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Verification

python
import pymongo
client = pymongo.MongoClient(&#39;localhost&#39;)
db = client[&#39;testdb&#39;]
db[&#39;table&#39;].insert({&#39;name&#39;:&#39;bob&#39;})
db[&#39;table&#39;].find_one({&#39;name&#39;:&#39;bob&#39;})

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3.3 redis (distributed crawler, maintain crawling queue)

Installation:

pip3 install redis

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Verification:

4. Tool library

4.1 flask (WEB library)

pip3 install flask

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4.2 Django (distributed crawler maintenance system)

pip3 install django

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4.3 jupyter (notepad running on the web page, supports markdown, and can run code on the web page)

pip3 install jupyter

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Verification:

After opening CMD

jupyter notebook

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, you can directly run the code on the web page Create notepad, code blocks and Markdown blocks, support printing

[Related recommendations]

1. Python crawler library and related tools

2. Python crawler introductory tutorial

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