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PORegex help: Identifying websites in text
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copied!<p>I am trying to write a function which removes websites from a piece of text. I have:</p> <pre><code>removeWebsites<- function(text){ text = gsub("(http://|https://|www.)[[:alnum:]~!#$%&+-=?,:/;._]*",'',text) return(text) } </code></pre> <p>This handles a large set of the problem, but not a popular one, i.e something of the form <code>xyz.com</code></p> <p>I do not wish to add <code>.com</code> at the end of the above regex, as it limits the scope of that regex. However I tried writing some more regexex like:</p> <pre><code>gsub("[[:alnum:]~!#$%&+-=?,:/;._]*.com",'',testset[10]) </code></pre> <p>This worked, but it also modified email ids of the form <code>abc@xyz.com</code> to <code>abc@</code>. I don't want this, so I modified it to </p> <pre><code>gsub("*((^@)[[:alnum:]~!#$%&+-=?,:/;._]*).com",'\\1',testset[10]) </code></pre> <p>This left the email ids alone but stopped recognising websites of the form <code>xyz.com</code></p> <p>I understand that I need some sort of a set difference here, of the form of what was explained <a href="https://stackoverflow.com/questions/9944361/aflex-regular-expression-difference">here</a> but I was not able to implement it (mainly because I was not able to completely understand it). Any idea on how I go about solving my problem?</p> <p>Edit: I tried negative lookaheads:</p> <pre><code>gsub("[[:alnum:]~!#$%&+-=?,:/;._](?!@)[^(?!.*@)]*.com",'',testset[10]) </code></pre> <p>I got a 'invalid regex' error. I believe a little help in correcting may get this to work...</p>

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