Keith S Weintraub
2014-Jan-29 14:29 UTC
[R] Best way to get the prices from these strings?
Folks, I got the following prices by scraping a web page just for my own edification: thePrices<- c("id=\"p0\">$69.95</div>", "id=\"p1\">$44.95</div>", "id=\"p2\">$69.95</div>", "id=\"p3\">$59.95</div>", "id=\"p4\">$69.95</div>", "id=\"p5\">$79.95</div>", "id=\"p6\">$89.95</div>", "id=\"p7\">$59.95</div>", "id=\"p8\">$59.95</div>", "id=\"p9\">$79.95</div>", "id=\"p10\">$79.95</div>", "id=\"p11\">$89.95</div>", "id=\"p12\">$89.95</div>", "id=\"p13\">$79.95</div>", "id=\"p14\">$89.95</div>", "id=\"p15\">$79.95</div>", "id=\"p16\">$39.95</div>", "id=\"p17\">$59.95</div>", "id=\"p18\">$69.95</div>", "id=\"p19\">$83.95</div>", "id=\"p20\">$73.95</div>", "id=\"p21\">$83.95</div>", "id=\"p22\">$93.95</div>", "id=\"p23\">$87.95</div>", "id=\"p24\">$91.95</div>", "id=\"p25\">$99.95</div>", "id=\"p26\">$61.95</div>\"" ) Using lapply and strsplit (twice) unlist etc. I was able to get the result I wanted (the prices as numbers e.g. 59.95) but I am sure that there is a much better way that someone might be able to point out for me. Note that I tried various regexes which didn't work. Is part of the difficulty that the strings in thePrices have multiple \"'s in them? Thanks for your time, Best, KW --
I am not sure if below ways are better. sub(".*>(.*)<.*","\\1",thePrices) sapply(thePrices, function(x){s=gregexpr(pattern ='\\$',x)[[1]][1];e=gregexpr(pattern ='<',x)[[1]][1];return(substr(x,s,e-1))}) On Wed, Jan 29, 2014 at 9:29 AM, Keith S Weintraub <kw1958@gmail.com> wrote:> Folks, > > I got the following prices by scraping a web page just for my own > edification: > > thePrices<- > c("id=\"p0\">$69.95</div>", "id=\"p1\">$44.95</div>", > "id=\"p2\">$69.95</div>", > "id=\"p3\">$59.95</div>", "id=\"p4\">$69.95</div>", > "id=\"p5\">$79.95</div>", > "id=\"p6\">$89.95</div>", "id=\"p7\">$59.95</div>", > "id=\"p8\">$59.95</div>", > "id=\"p9\">$79.95</div>", "id=\"p10\">$79.95</div>", > "id=\"p11\">$89.95</div>", > "id=\"p12\">$89.95</div>", "id=\"p13\">$79.95</div>", > "id=\"p14\">$89.95</div>", > "id=\"p15\">$79.95</div>", "id=\"p16\">$39.95</div>", > "id=\"p17\">$59.95</div>", > "id=\"p18\">$69.95</div>", "id=\"p19\">$83.95</div>", > "id=\"p20\">$73.95</div>", > "id=\"p21\">$83.95</div>", "id=\"p22\">$93.95</div>", > "id=\"p23\">$87.95</div>", > "id=\"p24\">$91.95</div>", "id=\"p25\">$99.95</div>", > "id=\"p26\">$61.95</div>\"" > ) > > Using lapply and strsplit (twice) unlist etc. I was able to get the result > I wanted (the prices as numbers e.g. 59.95) but I am sure that there is a > much better way that someone might be able to point out for me. > > Note that I tried various regexes which didn't work. > > Is part of the difficulty that the strings in thePrices have multiple \"'s > in them? > > Thanks for your time, > Best, > KW > > -- > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >[[alternative HTML version deleted]]
Hi Slight modification to get rid of $ as.numeric(gsub(".*\\$(.*)<.*","\\1",thePrices)) Petr> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r- > project.org] On Behalf Of dan wang > Sent: Wednesday, January 29, 2014 3:55 PM > To: Keith S Weintraub > Cc: r-help at r-project.org > Subject: Re: [R] Best way to get the prices from these strings? > > I am not sure if below ways are better. > > sub(".*>(.*)<.*","\\1",thePrices) > > sapply(thePrices, function(x){s=gregexpr(pattern > ='\\$',x)[[1]][1];e=gregexpr(pattern > ='<',x)[[1]][1];return(substr(x,s,e-1))}) > > > On Wed, Jan 29, 2014 at 9:29 AM, Keith S Weintraub <kw1958 at gmail.com> > wrote: > > > Folks, > > > > I got the following prices by scraping a web page just for my own > > edification: > > > > thePrices<- > > c("id=\"p0\">$69.95</div>", "id=\"p1\">$44.95</div>", > > "id=\"p2\">$69.95</div>", "id=\"p3\">$59.95</div>", > > "id=\"p4\">$69.95</div>", "id=\"p5\">$79.95</div>", > > "id=\"p6\">$89.95</div>", "id=\"p7\">$59.95</div>", > > "id=\"p8\">$59.95</div>", "id=\"p9\">$79.95</div>", > > "id=\"p10\">$79.95</div>", "id=\"p11\">$89.95</div>", > > "id=\"p12\">$89.95</div>", "id=\"p13\">$79.95</div>", > > "id=\"p14\">$89.95</div>", "id=\"p15\">$79.95</div>", > > "id=\"p16\">$39.95</div>", "id=\"p17\">$59.95</div>", > > "id=\"p18\">$69.95</div>", "id=\"p19\">$83.95</div>", > > "id=\"p20\">$73.95</div>", "id=\"p21\">$83.95</div>", > > "id=\"p22\">$93.95</div>", "id=\"p23\">$87.95</div>", > > "id=\"p24\">$91.95</div>", "id=\"p25\">$99.95</div>", > > "id=\"p26\">$61.95</div>\"" > > ) > > > > Using lapply and strsplit (twice) unlist etc. I was able to get the > > result I wanted (the prices as numbers e.g. 59.95) but I am sure > that > > there is a much better way that someone might be able to point out > for me. > > > > Note that I tried various regexes which didn't work. > > > > Is part of the difficulty that the strings in thePrices have multiple > > \"'s in them? > > > > Thanks for your time, > > Best, > > KW > > > > -- > > > > ______________________________________________ > > R-help at r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide > > http://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > and provide commented, minimal, self-contained, reproducible code.________________________________ Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou ur?eny pouze jeho adres?t?m. 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Here is another approach:> thePrices<-+ c("id=\"p0\">$69.95</div>", "id=\"p1\">$44.95</div>", "id=\"p2\">$69.95</div>", + "id=\"p3\">$59.95</div>", "id=\"p4\">$69.95</div>", "id=\"p5\">$79.95</div>", + "id=\"p6\">$89.95</div>", "id=\"p7\">$59.95</div>", "id=\"p8\">$59.95</div>", + "id=\"p9\">$79.95</div>", "id=\"p10\">$79.95</div>", "id=\"p11\">$89.95</div>", + "id=\"p12\">$89.95</div>", "id=\"p13\">$79.95</div>", "id=\"p14\">$89.95</div>", + "id=\"p15\">$79.95</div>", "id=\"p16\">$39.95</div>", "id=\"p17\">$59.95</div>", + "id=\"p18\">$69.95</div>", "id=\"p19\">$83.95</div>", "id=\"p20\">$73.95</div>", + "id=\"p21\">$83.95</div>", "id=\"p22\">$93.95</div>", "id=\"p23\">$87.95</div>", + "id=\"p24\">$91.95</div>", "id=\"p25\">$99.95</div>", "id=\"p26\">$61.95</div>\"" + )> require(gsubfn) > as.numeric(gsubfn(".*>.([0-9.]+).*", "\\1", thePrices))[1] 69.95 44.95 69.95 59.95 69.95 79.95 89.95 59.95 59.95 79.95 79.95 89.95 89.95 [14] 79.95 89.95 79.95 39.95 59.95 69.95 83.95 73.95 83.95 93.95 87.95 91.95 99.95 [27] 61.95>Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. On Wed, Jan 29, 2014 at 9:29 AM, Keith S Weintraub <kw1958 at gmail.com> wrote:> Folks, > > I got the following prices by scraping a web page just for my own edification: > > thePrices<- > c("id=\"p0\">$69.95</div>", "id=\"p1\">$44.95</div>", "id=\"p2\">$69.95</div>", > "id=\"p3\">$59.95</div>", "id=\"p4\">$69.95</div>", "id=\"p5\">$79.95</div>", > "id=\"p6\">$89.95</div>", "id=\"p7\">$59.95</div>", "id=\"p8\">$59.95</div>", > "id=\"p9\">$79.95</div>", "id=\"p10\">$79.95</div>", "id=\"p11\">$89.95</div>", > "id=\"p12\">$89.95</div>", "id=\"p13\">$79.95</div>", "id=\"p14\">$89.95</div>", > "id=\"p15\">$79.95</div>", "id=\"p16\">$39.95</div>", "id=\"p17\">$59.95</div>", > "id=\"p18\">$69.95</div>", "id=\"p19\">$83.95</div>", "id=\"p20\">$73.95</div>", > "id=\"p21\">$83.95</div>", "id=\"p22\">$93.95</div>", "id=\"p23\">$87.95</div>", > "id=\"p24\">$91.95</div>", "id=\"p25\">$99.95</div>", "id=\"p26\">$61.95</div>\"" > ) > > Using lapply and strsplit (twice) unlist etc. I was able to get the result I wanted (the prices as numbers e.g. 59.95) but I am sure that there is a much better way that someone might be able to point out for me. > > Note that I tried various regexes which didn't work. > > Is part of the difficulty that the strings in thePrices have multiple \"'s in them? > > Thanks for your time, > Best, > KW > > -- > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
You could use ?gsub() or library(qdap) as.numeric(unlist(genXtract(thePrices,">$","<"))) # [1] 69.95 44.95 69.95 59.95 69.95 79.95 89.95 59.95 59.95 79.95 79.95 89.95 #[13] 89.95 79.95 89.95 79.95 39.95 59.95 69.95 83.95 73.95 83.95 93.95 87.95 #[25] 91.95 99.95 61.95 A.K. On Wednesday, January 29, 2014 9:33 AM, Keith S Weintraub <kw1958 at gmail.com> wrote: Folks, I got the following prices by scraping a web page just for my own edification: thePrices<- c("id=\"p0\">$69.95</div>", "id=\"p1\">$44.95</div>", "id=\"p2\">$69.95</div>", "id=\"p3\">$59.95</div>", "id=\"p4\">$69.95</div>", "id=\"p5\">$79.95</div>", "id=\"p6\">$89.95</div>", "id=\"p7\">$59.95</div>", "id=\"p8\">$59.95</div>", "id=\"p9\">$79.95</div>", "id=\"p10\">$79.95</div>", "id=\"p11\">$89.95</div>", "id=\"p12\">$89.95</div>", "id=\"p13\">$79.95</div>", "id=\"p14\">$89.95</div>", "id=\"p15\">$79.95</div>", "id=\"p16\">$39.95</div>", "id=\"p17\">$59.95</div>", "id=\"p18\">$69.95</div>", "id=\"p19\">$83.95</div>", "id=\"p20\">$73.95</div>", "id=\"p21\">$83.95</div>", "id=\"p22\">$93.95</div>", "id=\"p23\">$87.95</div>", "id=\"p24\">$91.95</div>", "id=\"p25\">$99.95</div>", "id=\"p26\">$61.95</div>\"" ) Using lapply and strsplit (twice) unlist etc. I was able to get the result I wanted (the prices as numbers e.g. 59.95)? but I am sure that there is a much better way that someone might be able to point out for me. Note that I tried various regexes which didn't work. Is part of the difficulty that the strings in thePrices have multiple \"'s in them? Thanks for your time, Best, KW -- ______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.