CODEWITHSUNDEEP
regexrsubstring
user3456230
user3456230

Reputation: 217

Remove row if it starts with "RT"

How can I remove the entire row for those which start with "RT" in the first column?

    structure(list(text = structure(c(4L, 6L, 1L, 2L, 5L, 3L), .Label = c("@AirAsia @AirAsiaId finally they let us fly with 9.20 flight today. Manual boarding pass. Phew, that was a great relief!", 
    "@AirAsia your direct debit (Maybank) payment gateways is not working. Is it something you are working to fix?", 
    "RT @AirAsia: Kindly note that CIMB Direct Debit service will be unavailable tonight from (GMT+8) 1145hrs on 31 Jan until 0600hrs on 3 Feb 2…", 
    "RT @AirAsia: Skipped breakfast this morning? Now you can enjoy a great breakfast onboard with our new breakfast meals! http://t.co/957ZaLjY…", 
    "xdek ke flight @AirAsia Malaysia to LA... hahah..bagi la promo murah2 sikit, kompom aku beli...", 
    "You know there is a problem when customer service asks you to wait for 103 minutes and your no is 42 in the queue. @AirAsia"
    ), class = "factor"), created = structure(c(5L, 4L, 4L, 3L, 2L, 
    1L), .Label = c("1/2/2014 16:14", "1/2/2014 17:00", "3/2/2014 0:54", 
    "3/2/2014 0:58", "3/2/2014 1:28"), class = "factor")), .Names = c("text", 
    "created"), class = "data.frame", row.names = c(NA, -6L))

Upvotes: 2

Views: 560

Answers (4)

Neal Fultz
Neal Fultz

Reputation: 9687

All of the above work, I prefer subset because it is a bit more legible:

no.rts <- subset( tweets, ! grepl("^RT ", text) )

Upvotes: 0

Rich Scriven
Rich Scriven

Reputation: 99341

grepl also works. Assuming d is the data set,

> d[!grepl("^RT", d$text), ]
##                        text        created
## 2 You know there...@AirAsia  3/2/2014 0:58
## 3 @AirAsia... great relief!  3/2/2014 0:58
## 4 @AirAsia...orking to fix?  3/2/2014 0:54
## 5 xdek ke flight ...        1/2/2014 17:00

Upvotes: 4

bartektartanus
bartektartanus

Reputation: 16080

Or use stri_sub function from stringi package to get first two characters and then check if they are equal to "RT":

require(stringi)
df[stri_sub(df$text,1,2)!="RT",]

Upvotes: 0

hrbrmstr
hrbrmstr

Reputation: 78812

Assuming your data frame is called tweets, then

no.rts <- tweets[grep("^RT ", tweets$text, invert=TRUE),]

will do what you want (and put the results in a new data frame called no.rts).

The grep statement says to ignore all lines in tweets$text that begin (^) with RT. Without the invert=TRUE it would select all the lines beginning with RT.

Upvotes: 4

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