Python正則表達式查找行包含特定類型的文件名

Question

我有一個文本文件。只有當文件名是.doc或.pdf類型文件時，我纔想得到包含文件名的行。使用python re.findall()

例如，

<TR><TD ALIGN="RIGHT">4.</TD> 
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="ABC.pdf"> On Complex Analytic Manifolds</a></TD> 
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=72>L. Sam</TD> 
</TR> 
<TR><TD ALIGN="RIGHT">5.</TD> 
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="DEF.doc"> On the Geometric theory of Fields</a>*</TD> 
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=72>G.K. Ram</TD> 
</TR> 

我想以下行。

<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="ABC.pdf"> On Complex Analytic Manifolds</a></TD> 
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="DEF.doc"> On the Geometric theory of Fields</a>*</TD> 

任何機構可以告訴我任何可擴展的方式在re.findall定義模式（）？

Answer 1

事情是這樣的：

>>> strs="""<TR><TD ALIGN="RIGHT">4.</TD> 
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="ABC.pdf"> On Complex Analytic Manifolds</a></TD> 
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=72>L. Sam</TD> 
</TR> 
<TR><TD ALIGN="RIGHT">5.</TD> 
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="DEF.doc"> On the Geometric theory of Fields</a>*</TD> 
<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=72>G.K. Ram</TD> 
</TR>""" 

>>> [x for x in strs.splitlines() if re.search(r"[a-zA-Z0-9]+\.(pdf|doc)",x)] 
['<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="ABC.pdf"> On Complex Analytic Manifolds</a></TD>', 
'<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="DEF.doc"> On the Geometric theory of Fields</a>*</TD>' 
] 

Answer 2

你可以使用這個表達式：

(.*?<a\shref=[\"']\w+(?:\.doc|\.pdf)[\"']>.*) 

輸出：

>>> html = """<TR><TD ALIGN="RIGHT">4.</TD> 
... <TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="ABC.pdf"> On Complex Analytic Manifolds</a></TD> 
... <TD ALIGN="LEFT" VALIGN="TOP" WIDTH=72>L. Sam</TD> 
... </TR> 
... <TR><TD ALIGN="RIGHT">5.</TD> 
... <TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="DEF.doc"> On the Geometric theory of Fields</a>*</TD> 
... <TD ALIGN="LEFT" VALIGN="TOP" WIDTH=72>G.K. Ram</TD> 
... </TR>""" 
>>> re.findall("(.*?<a\shref=[\"']\w+(?:\.doc|\.pdf)[\"']>.*)", html) 
['<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="ABC.pdf"> On Complex Analytic Manifolds</a></TD>', '<TD ALIGN="LEFT" VALIGN="TOP" WIDTH=50%><a href="DEF.doc"> On the Geometric theory of Fields</a>*</TD>'] 

Answer 3

您可以同時使用BeautifulSoup和re。

import BeautifulSoup 
import re 

lines = soup.findAll('href', text = re.compile('your regex here'), attrs = {'class' : 'text'}) 

與class您在html代碼中的高級標題。