python基础篇-爬虫urlparse使用及简单示例

>>> from urllib.parse import urlparse
>>> o = urlparse('http://www.cwi.nl:80/%7Eguido/Python.html')
>>> o   
ParseResult(scheme='http', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html',
            params='', query='', fragment='')
>>> o.scheme
'http'
>>> o.port
80
>>> o.geturl()
'http://www.cwi.nl:80/%7Eguido/Python.html'

>>> from urllib.parse import urlparse
 >>> urlparse('//www.cwi.nl:80/%7Eguido/Python.html')
 ParseResult(scheme='', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html',
            params='', query='', fragment='')
 >>> urlparse('www.cwi.nl/%7Eguido/Python.html')
 ParseResult(scheme='', netloc='', path='www.cwi.nl/%7Eguido/Python.html',
            params='', query='', fragment='')
 >>> urlparse('help/Python.html')
 ParseResult(scheme='', netloc='', path='help/Python.html', params='',
            query='', fragment='')

　　

Attribute	Index	Value	Value if not present
scheme	0	URL scheme specifier	scheme parameter
netloc	1	Network location part	empty string
path	2	Hierarchical path	empty string
params	3	Parameters for last path element	empty string
query	4	Query component	empty string
fragment	5	Fragment identifier	empty string
username		User name	None
password		Password	None
hostname		Host name (lower case)	None
port		Port number as integer, if present	None

>>>from urllib.parse import urljoin
>>>urljoin('http://www.cwi.nl/%7Eguido/Python.html', 'FAQ.html')
'http://www.cwi.nl/%7Eguido/FAQ.html'

>>> urljoin('http://www.cwi.nl/%7Eguido/Python.html',
...         '//www.python.org/%7Eguido')
'http://www.python.org/%7Eguido'

　　

>>>urllib.request.quote('http://www.baidu.com')
'http%3A//www.baidu.com'

>>>urllib.request.unquote('http%3A//www.baidu.com')
'http://www.baidu.com'

　　

简单的demo示例

思路如下：

1. 爬取一个网页并将爬取到的内容读取出来赋给一个变量。
2. 以写入的方式打开一个本地文件，命名为*.html等网页格式。
3. 将步骤1中的变量写入该文件中。
4. 关闭该文件

import urllib.request
import urllib.parse

url='http://www.baidu.com'
hearder={
'User-Agent':'Mozilla/5.0 (X11; Fedora; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36'
}

request=urllib.request.Request(url,headers=header)
reponse=urllib.request.urlopen(request).read()

h=open("./1.html","wb")
h.write(reponse)
h.close()

　

参考：https://docs.python.org/3/library/urllib.parse.html?highlight=urlparse#urllib.parse.urlparse

         https://blog.csdn.net/fengxinlinux/article/details/77281253

         https://www.runoob.com/python/python-func-open.html