Python通读文件直到匹配,读到下一个模式
作者：互联网
Python 2.4.3
我需要读一些文件(可以大到10GB).我需要它做的是浏览文件,直到它匹配模式.然后打印该行以及后面的每一行,直到它与另一个模式匹配.此时,继续读取文件直到下一个模式匹配.
例如.文件包含.
---- Alpha ---- Zeta
...(text lines)
---- Bravo ---- Delta
...(text lines)
等等
如果匹配—- Alpha —- Zeta,它应该打印—- Alpha —- Zeta和之后的每一行直到它遇到—- Bravo —- Delta(或者除了—-阿尔法—- Zeta),它会直接读到它直到匹配—-阿尔法—-泽塔再次.
以下匹配我正在寻找的 – 但只打印匹配行 – 而不是它后面的文本.
知道我哪里出错吗？
import re
fh = open('text.txt', 'r')
re1='(-)' # Any Single Character 1
re2='(-)' # Any Single Character 2
re3='(-)' # Any Single Character 3
re4='(-)' # Any Single Character 4
re5='( )' # White Space 1
re6='(Alpha)' # Word 1
re6a='((?:[a-z][a-z]+))' # Word 1 alternate
re7='( )' # White Space 2
re8='(-)' # Any Single Character 5
re9='(-)' # Any Single Character 6
re10='(-)' # Any Single Character 7
re11='(-)' # Any Single Character 8
re12='(\\s+)' # White Space 3
re13='(Zeta)' # Word 2
re13a='((?:[a-z][a-z]+))' # Word 2 alternate
rg = re.compile(re1+re2+re3+re4+re5+re6+re7+re8+re9+re10+re11+re12+re13,re.IGNORECASE|re.DOTALL)
rga = re.compile(re1+re2+re3+re4+re5+re6a+re7+re8+re9+re10+re11+re12+re13a,re.IGNORECASE|re.DOTALL)
for line in fh:
if re.match(rg, line):
print line
fh.next()
while not re.match(rga, line):
print fh.next()
fh.close()
和我的示例文本文件.
---- Pappa ---- Oscar
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris eleifend imperdiet
lacus quis imperdiet. Nulla erat neque, laoreet vel fermentum a, dapibus in sem.
Maecenas elementum nisi nec neque pellentesque ac rutrum urna cursus. Nam non purus
sit amet dolor fringilla venenatis. Integer augue neque, scelerisque ac dictum at,
venenatis elementum libero. Etiam nec ante in augue porttitor laoreet. Aenean ultrices
pellentesque erat, id porta nulla vehicula id. Cras eu ante nec diam dapibus hendrerit
in ac diam. Vivamus velit erat, tincidunt id tempus vitae, tempor vel leo. Donec
aliquam nibh mi, non dignissim justo.
---- Alpha ---- Zeta
Sed molestie tincidunt euismod. Morbi ultrices diam a nibh varius congue. Nulla velit
erat, luctus ac ornare vitae, pharetra quis felis. Sed diam orci, accumsan eget
commodo eu, posuere sed mi. Phasellus non leo erat. Mauris turpis ipsum, mollis sed
ismod nec, aliquam non quam. Vestibulum sem eros, euismod ut pharetra sit amet,
dignissim eget leo.
---- Charley ---- Oscar
Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus.
Aliquam commodo, metus at vulputate hendrerit, dui justo tempor dui, at posuere
ante vitae lorem. Fusce rutrum nibh a erat condimentum laoreet. Nullam eu hendrerit
sapien. Suspendisse id lobortis urna. Maecenas ut suscipit nisi. Proin et metus at
urna euismod sollicitudin eu at mi. Aliquam ac egestas magna. Quisque ac vestibulum
lectus. Duis ac libero magna, et volutpat odio. Cras mollis tincidunt nibh vel rutrum.
Curabitur fringilla, ante eget scelerisque rhoncus, libero nisl porta leo, ac
vulputate mi erat vitae felis. Praesent auctor fringilla rutrum. Aenean sapien ligula,
imperdiet sodales ullamcorper ut, vulputate at enim.
---- Bravo ---- Delta
Donec cursus tincidunt pellentesque. Maecenas neque nisi, dignissim ac aliquet ac,
vestibulum ut tortor. Pellentesque habitant morbi tristique senectus et netus et
malesuada fames ac turpis egestas. Aenean ullamcorper dapibus accumsan. Aenean eros
tortor, ultrices at adipiscing sed, lobortis nec dolor. Fusce eros ligula, posuere
quis porta nec, rhoncus et leo. Curabitur turpis nunc, accumsan posuere pulvinar eget,
sollicitudin eget ipsum. Sed a nibh ac est porta sollicitudin. Pellentesque ut urna ut
risus pharetra mollis tincidunt sit amet sapien. Sed semper sollicitudin eros quis
pellentesque. Curabitur ac metus lorem, ac malesuada ipsum. Nulla turpis erat, congue
eu gravida nec, egestas id nisi. Praesent tellus ligula, pretium vitae ullamcorper
vitae, gravida eu ipsum. Cras sed erat ligula.
---- Alpha ---- Zeta
Cras id condimentum lectus. Sed sit amet odio eros, ut mollis sapien. Etiam varius
tincidunt quam nec mattis. Nunc eu varius magna. Maecenas id ante nisl. Cras sed augue
ipsum, non mollis velit. Fusce eu urna id justo sagittis laoreet non id urna. Nullam
venenatis tincidunt gravida. Proin mattis est sit amet dolor malesuada sagittis.
Curabitur in lacus rhoncus mi posuere ullamcorper. Phasellus eget odio libero, ut
lacinia orci. Pellentesque iaculis, ligula at varius vulputate, arcu leo dignissim
massa, non adipiscing lectus magna nec dolor. Quisque in libero nec orci vestibulum
dapibus. Nulla turpis massa, varius quis gravida eu, bibendum et nisl. Fusce tincidunt
laoreet elit, sed egestas diam pharetra eget. Maecenas lacus velit, egestas nec tempor
eget, hendrerit et massa.
更新
下面的代码确实有效 – 它在标题类型行上匹配 – 打印它后面的每一行直到下一个标题类型模式 – 这是不匹配的,跳过下一个标题类型模式.
唯一的问题是 – 它确实非常慢.通过10米线路需要大约一分钟.
re1='(-)' # Any Single Character 1
re2='(-)' # Any Single Character 2
re3='(-)' # Any Single Character 3
re4='(-)' # Any Single Character 4
re5='( )' # White Space 1
re6='(Alpha)' # Word 1
re6a='((?:[a-z][a-z]+))' # Word 1 alternate
re7='( )' # White Space 2
re8='(-)' # Any Single Character 5
re9='(-)' # Any Single Character 6
re10='(-)' # Any Single Character 7
re11='(-)' # Any Single Character 8
re12='(\\s+)' # White Space 3
re13='(Zeta)' # Word 2
re13a='((?:[a-z][a-z]+))' # Word 2 alternate
rg = re.compile(re1+re2+re3+re4+re5+re6+re7+re8+re9+re10+re11+re12+re13,re.IGNORECASE|re.DOTALL)
rga = re.compile(re1+re2+re3+re4+re5+re6a+re7+re8+re9+re10+re11+re12+re13a,re.IGNORECASE|re.DOTALL)
linestop = 0
fh = open('test.txt', 'r')
for line in fh:
if linestop == 0:
if re.match(rg, line):
print line
linestop = 1
else:
if re.match(rga, line):
linestop = 0
else:
print line
fh.close()
如果我首先添加一个grep部分,我认为这会极大地提高速度.即grep out – 然后运行上面的正则表达式脚本.
我让os.system运行良好 – 我无法看到如何通过pOpen传递正则表达式匹配
****最终更新**********
我称这完成了.我最终做的是：
>使用os.system浏览文件 – 并将结果写出来.
>读取文件并使用我上面的re.match – 只打印出必要的项目.
最终结果是从大约65秒读取1000万行文件 – 打印出必要的项目 – 大约3.5秒.我希望我能想出如何传递grep而不是os.system – 但也许它在python 2.4中没有得到很好的启发
解决方法:
你仍然匹配线,它不会改变,因为你仍然在for循环的同一个迭代中.
标签：python,regex,pattern-matching 来源： https://codeday.me/bug/20190903/1794549.html