82 lines
1.9 KiB
Markdown
82 lines
1.9 KiB
Markdown
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# BeautifulSoup 简介
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> 原文：<https://www.pythonforbeginners.com/beautifulsoup/python-beautifulsoup-basic>
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### 什么是 BeautifulSoup？
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```py
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BeautifulSoup is a Python library from [www.crummy.com](http://www.crummy.com/software/BeautifulSoup/ "crummy")
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```
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### 它能做什么
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```py
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On their website they write "Beautiful Soup parses anything you give it, and does the tree traversal stuff for you.
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**You can tell it to:**
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"Find all the links"
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"Find all the links of class externalLink"
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"Find all the links whose urls match "foo.com"
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"Find the table heading that's got bold text, then give me that text.""
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```
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### 美丽的例子
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```py
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In this example, we will try and find a link (a tag) in a webpage.
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Before we start, we have to import two modules. (BeutifulSoup and urllib2).
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Urlib2 is used to open the URL we want.
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We will use the soup.findAll method to search through the soup object to match fortext and html tags within the page.
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```
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```py
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from BeautifulSoup import BeautifulSoup
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import urllib2
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url = urllib2.urlopen("http://www.python.org")
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content = url.read()
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soup = BeautifulSoup(content)
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links = soup.findAll("a")
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```
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##### 输出
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```py
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That will print out all the elements in python.org with an "a" tag.
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(The "a" tag defines a hyperlink, which is used to link from one page to another.)
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```
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### 美丽组图示例 2
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```py
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To make it a bit more useful, we can specify the URL's we want to return.
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```
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```py
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from BeautifulSoup import BeautifulSoup
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import urllib2
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import re
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url = urllib2.urlopen("http://www.python.org")
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content = url.read()
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soup = BeautifulSoup(content)
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for a in soup.findAll('a',href=True):
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if re.findall('python', a['href']):
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print "Found the URL:", a['href']
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```
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##### 进一步阅读
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```py
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I recommend that you head over to [http://www.crummy.com](http://www.crummy.com/software/BeautifulSoup/ "Crummy") to read more about what you can do with this awesome module.
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```
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