Python 2.4.3
I need to read through some files (can be as large as 10GB). What I need it to do is go through the file until it matches a pattern. Then print that line and every line after it until it matches another pattern. At that point, resume reading through the file until the next pattern match.
For example. file contains.
---- Alpha ---- Zeta
...(text lines)
---- Bravo ---- Delta
...(text lines)
etc.
If matching on —- Alpha —- Zeta, it should print —- Alpha —- Zeta and every line after that until it encounters —- Bravo —- Delta (or whatever other than —- Alpha —- Zeta), which it will read right on by it until it matches —- Alpha —- Zeta again.
The following matches what i’m looking for – but only prints the matching line – and not the text that follows it.
Any idea where I’m going wrong on it?
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()
and my example text file.
---- 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.
+++++++++++++++++++++ Update ++++++++++++++++++++++++++++++++
The following code does work – it matches on the header type row – prints that and every line after it until the next header type pattern – which is that doesn’t match, skips until the next header type pattern.
Only problem is – it’s really really butt slow. It takes about a minute to do through 10m lines.
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()
+++++++++ If I add a grep part to it first, i’m thinking that’ll speed things up tremendously. i.e. grep out – then run the above regex script.
I got os.system to work good – I can’t see how to pass a regex match via pOpen
**** Final Update **********
I’m calling this completed. What I ended up doing was:
- Grep through the file using os.system – and writing the results out.
- reading the file in and using the re.match I have for above – printing out only the necessary items.
net result was it went from taking about 65 seconds to read through a 10 million line file – printing out the necessary items – to about 3.5 seconds. I wish I could have figured out how to pass grep other than os.system – but maybe it’s just not well implimented in python 2.4
You’re still matching against line, which doesn’t change because you’re still in the same iteration of the for loop.