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I am attempting to locate(then extract) a repeated phrase by using the below code. I require phrases beginning with "approximately" and ending in "closed".

For example "approximately $162.9 million in total assets and $144.5 million in total deposits was closed"

str_locate(x,"(\b[Aa]pproximately\b)(.*)(\b[Cc]losed\b)")

str_extract(x,"(\b[Aa]pproximately\b)(.*)(\b[Cc]losed\b)")

The above code returns NA for phrase start and end points. Here is a sample of the character vector where the phrases are located.(it is a webpage of publicly available FDIC information)

"206-4662).\r\n\r\nDecember \r\n\r\n\r\n Western National Bank, Phoenix, AZ with approximately $162.9 million in total assets and $144.5 million in total deposits was closed. Washington Federal, Seattle, WA has agreed to assume all deposits excluding certain brokered deposits.\r\n(PR-195-2011) \r\n\r\n\r\n\r\n Premier Community Bank of the Emerald Coast, Crestview, FL with approximately $126.0 million in total assets and $112.1 million in total deposits was closed. Summit Bank, N.A., Panama City, FL has agreed to assume all deposits.\r\n(PR-194-2011)"

I may be using reg expression incorrectly as i am new to it so any advice much appreciated.

Tim Pietzcker
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barryq
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1 Answers1

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\b is ASCII backspace. You need to escape the backslashes if you want it to mean "word boundary":

str_locate(x,"(\\b[Aa]pproximately\\b)(.*)(\\b[Cc]losed\\b)")

Also, you don't need the parentheses around your keywords, unless you want to check their capitalization later. And you can match case-insensitively with the (?i) modifier when using the perl() function for your regexes.

Lastly, be aware that .* will not match if there are newlines between approximately and closed (this can be fixed with (?s)), and it may yield unwanted results if more than one pair of keywords is present in the string.

Therefore, you should probably change your regex to

str_locate(x, perl("(?is)\\bapproximately\\b(.*?)\\bclosed\\b"))
Tim Pietzcker
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  • Thanks for swift response Tim, Could you possibly elaborate on how to encompass the perl function within str_locate() ? This particular package doesnt seems to have perl options within it – barryq Sep 25 '12 at 14:44
  • @user1176697: It isn't? But it's described [in the manual](http://cran.r-project.org/web/packages/stringr/stringr.pdf), page 4. – Tim Pietzcker Sep 25 '12 at 15:08