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Python regular expression

Hi all,

I have data like the following which I wish to process using a regular expression:

KEYWORD1 VARIABLE_1;
KEYWORD1 VARIABLE_2;
KEYWORD2 VARIABLE_3;
KEYWORD2 VARIABLE_4;

So i use the following:

temp1 = re.compile('\s*KEYWORD1\s+(\S+)')
temp2 = re.compile('\s*KEYWORD2\s+(\S+)')

Using this its straight forward to extract and store the VARIABLE_1 to VARIABLE_4, however I sometimes have the following structure

KEYWORD1 [1_OR_MORE_NUMBERS:0] VARIABLE_5;
KEYWORD1 [1_OR_MORE_NUMBERS:0] VARIABLE_6;

I can't seem to devise a regular expression that nicely extracts and stores all the variables - any thoughts?

ozo

do you want to skip over the [1_OR_MORE_NUMBERS:0] or do you want to extract it together with the VARIABLE_5?

trican

ASKER

Hi ozo,

I want to skip over [1_OR_MORE_NUMBERS:0]

HonorGod

by 1 or more numbers, do you mean 1 or more digits?

temp1 = re.compile('\s*KEYWORD1\s+(\d+:0)?(\S+)')

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trican

ASKER

yes one or more digits

ozo

to skip over things in [] you might use
'\s*KEYWORD2(?:\[.*?\]|\s)+(\S+)'
to get the last \S+ before the ; you might use
'\s*KEYWORD2\s.*?(\S+);'

HonorGod

Are the square brackets actually there?

temp1 = re.compile('\s*KEYWORD1\s+(?\[\d+:0])?(\S+)')

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trican

ASKER

yes the square brackets are there

trican

ASKER

still not quite working? I suspect its very close

ozo

what is not working, and in what way is it not working?

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ozo

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SOLUTION

ghostdog74

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ghostdog74

also, the check for KEYWORD in a string, use the "in" operator

for line in open("file"):
   if "KEYWORD" in line : # or if line.startswith("KEYWORD")
       #do something

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trican

ASKER

ozo,

I think its workin ok now - I was confused that I could always use group(2) to access the information that I needed. If you could explain why this work in this manner all the points are yours.

Also thanks ghostdog, whilst i agree not using regular epxressions is more readable I actually need the flexibility it gives.

SOLUTION

pepr

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