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Please help me get past this problem

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Join Date: Nov 2009

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Reputation: P00dle is an unknown quantity at this point

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P00dle

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Junior Poster in Training

Please help me get past this problem

Nov 4th, 2009

Hi.

First, I'll explain my task:
I have 4 text files. 3 of the files contain xml tags and content. The 4th is empty.
I need to read the 3 files, and write them to the 4th file. The reason for having 3 files is that the first and the last files both only have to be used once. The 2nd file has to be repeated a user-specified amount of times.

Initially my problem was that I had \'s in the text, and didnt know how to use regular expressions to escape them. That as been solved via DaniWeb

I have since advanced the code a bit, but am now stuck again. The body(2nd text file) needs to be repeated a certain amount of times. This can be done with a counter. Easy. The problem is that the xml in the text file contains an "id" tag that needs to hold the count value for every repition, in order to be unique. I can't figure out how to use regular expressions to find that tag and give it the value. Let's pretend the tag looks like this: <%%>CNT1</%%>

I need to replace <%%>CNt1</%%> with
<id>"value of count"</id>

My code, so far, looks like this:

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import re
special = re.compile(r"\\")
 
# This section writes the prefix to the text file
foo = open("PREFIX.txt", "r+")
text = foo.read()
foo.close()
 
def escape(match):
    return "\\" + match.group(0)            
 
#if __name__ == "__main__": <-- might need this in the future
out = open("2Bxml.txt", "w")
out.writelines(special.sub(escape, text))
out.writelines("\n")
out.close()
 
count1 = int(raw_input("Specify the number of repitations(e.g. \"1000\" will count from 1 to 999)"))
 
# This sections writes the suffix to the text file
foo3 = open("SUFFIX.txt", "r+")
text3 = foo3.read()
foo3.close()
 
def escape(match):
    return "\\" + match.group(0)
 
out3 = open("2Bxml.txt", "a") # This must append, not just write
out3.writelines(special.sub(escape, text3))
out3.close()
import re
special = re.compile(r"\\")

# This section writes the prefix to the text file
foo = open("PREFIX.txt", "r+")
text = foo.read()
foo.close()

def escape(match):
    return "\\" + match.group(0)            

#if __name__ == "__main__": <-- might need this in the future
out = open("2Bxml.txt", "w")
out.writelines(special.sub(escape, text))
out.writelines("\n")
out.close()

count1 = int(raw_input("Specify the number of repitations(e.g. \"1000\" will count from 1 to 999)"))

# This sections writes the suffix to the text file
foo3 = open("SUFFIX.txt", "r+")
text3 = foo3.read()
foo3.close()

def escape(match):
    return "\\" + match.group(0)

out3 = open("2Bxml.txt", "a") # This must append, not just write
out3.writelines(special.sub(escape, text3))
out3.close()

Its works just fine. Can I use the existing regular expression code to do what I need to? Please help!

Thanks!

Last edited by P00dle; Nov 4th, 2009 at 6:42 am.

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Join Date: Oct 2006

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vishesh

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Nearly a Posting Virtuoso

Nov 4th, 2009

Your regular expression would look like this:

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<%%>CNT(\d)+</%%>

We have put digits in a group.

And substitue it with <id>\\1</id> using sub method in re class. Here "\\1" indicated the group of above expression.

He