[R] a grep/regexpr problem
Gabor Grothendieck
ggrothendieck at myway.com
Sat Feb 7 04:00:08 CET 2004
Try this:
gsub(".*{|}","",s)
which deletes everything up to and including the { and then deletes
the }.
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Date: Fri, 06 Feb 2004 13:49:30 -0500
From: Rajarshi Guha <rxg218 at psu.edu>
To: R <r-help at stat.math.ethz.ch>
Subject: [R] a grep/regexpr problem
Hi,
I'm trying to parse lines of the form:
dan001.hin (0): fingerprint={256, 411, 426, 947, 973, 976}
What I need is the sequence of number between {}. I'm using grep as
match <- grep("{([0-9,\s]*)}",s,perl=T,value=T)
where s is a character vector.
But all I get is the whole string s. I tried using regexpr in an attempt
to get just the sequence I wanted:
match <- regexpr("{([0-9,\s]*)}", s , perl=T)
but then I get -1 as the return value indicating that there was no
match.
If grep is able to return the matched element (though I dont know why
the whole string is being returned) why is regexpr failing?
Finally, could anybody provide a hint as to how I should modify the
regex to get the sequence between {}. (I've used the same regex in
Python code to get the sequence and it works fine.)
Thanks,
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Rajarshi Guha <rxg218 at psu.edu> <http://jijo.cjb.net>;
GPG Fingerprint: 0CCA 8EE2 2EEB 25E2 AB04 06F7 1BB9 E634 9B87 56EE
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Entropy requires no maintenance.
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