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Error matching regular expression patterns to extract text into two columns of data frame

Consider the following hypothetical data:

x <- "There is a horror movie running in the iNox theater. : If row names are supplied of length one and the data 
frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). 
If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify 
the row names and not a column (by name or number) Can we go : Please"


y <- "There is a horror movie running in the iNox theater. If row names are supplied of length one and the data 
frame has a single row, the row.names is taken. To specify the row names and not a column. By name or number. : 
If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify 
the row names and not a column (by name or number) Can we go : Please"

z <- "There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). 
If row names are supplied of length one. : And the data frame has a single row, the row.names is taken to specify 
the row names and not a column (by name or number) Can we go : Please"

df <- data.frame(Text = c(x, y, z), row.names = NULL, stringsAsFactors = F)

You noticed that there is a ":" in different places. For instance:

  • In 'x' it (":") is after the first sentence.
  • In 'y' it is (":") after the fourth sentence.
  • and In 'z' after the sixth sentence.
  • In addition, before the last sentence in each text there is one more thing: "

What I want to do is create two columns that:

  • Only the first ":" and NOT THE LAST is considered.
  • If the first three sentences have ":", divide all the text into two columns, otherwise save the text in the second column and "NA" in the first column.

Required output for 'x':

 Col1                                                        Col2 
 There is a horror movie running in the iNox theater.        If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please

"y" ( ":" , ):

 Col1     Col2 
 NA       There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken. To specify the row names and not a column. By name or number. : If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please

"y" , Wanted Output "z" :

  Col1    Col2
  NA      all of the text from 'z'

:

resX <- data.frame(Col1 = gsub("\\s\\:.*$","\\1", df$Text[[1]]), 
           Col2 = gsub("^[^:]+(?:).\\s","\\1", df$Text[[1]]))

resY <- data.frame(Col1 = gsub("\\s\\:.*$","\\1", df$Text[[2]]), 
           Col2 = gsub("^[^:]+(?:).\\s","\\1", df$Text[[2]]))

resZ <- data.frame(Col1 = gsub("\\s\\:.*$","\\1", df$Text[[3]]), 
           Col2 = gsub("^[^:]+(?:).\\s","\\1", df$Text[[3]]))

"resDF" rbind.

:

  • for() .
  • "y" "z" , ( ).
+4
4

:

^(?s)(?!(?:(?:[^:]*?\\.){3,}))(.*?):(.*)$

Regex Demo

:

, true, 2

1 : 2 .

, 2 , , 1

, data process, . , col1 col2.... y z ... NA col1 col2.

→ ideone:

library(stringr)

    x <- "There is a horror movie running in the iNox theater. : If row names are supplied of length one and the data 
    frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). 
    If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify 
    the row names and not a column (by name or number) Can we go : Please"


    y <- "There is a horror movie running in the iNox theater. If row names are supplied of length one and the data 
    frame has a single row, the row.names is taken. To specify the row names and not a column. By name or number. : 
    If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify 
    the row names and not a column (by name or number) Can we go : Please"

    z <- "There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). 
    If row names are supplied of length one. : And the data frame has a single row, the row.names is taken to specify 
    the row names and not a column (by name or number) Can we go : Please"             


df <- data.frame(Text = c(x, y, z), row.names = NULL, stringsAsFactors = F)

resDF <- data.frame("Col1" = character(), "Col2" = character(), stringsAsFactors=FALSE)

   processData <- function(a) {
        patt <- "^(?s)(?!(?:(?:[^:]*?\\.){3,}))(.*?):(.*)$"    
        if(grepl(patt,a,perl=TRUE))
        {
            result<-str_match(a,patt)    
            col1<-result[2]
            col2<-result[3]
        }
        else
        {
            col1<-"NA"
            col2<-a
        }
       return(c(col1,col2))

    }



for (i in 1:nrow(df)){
tmp <- df[i, ]
resDF[nrow(resDF) + 1, ] <- processData(tmp)
}    


print(resDF)

:

                                                   Col1
1 There is a horror movie running in the iNox theater. 
2                                                    NA
3                                                    NA
                                                                                                                                                                                                                                                                                                                                                                                                                              Col2
1                                                        If row names are supplied of length one and the data \n    frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). \n    If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify \n    the row names and not a column (by name or number) Can we go : Please
2 There is a horror movie running in the iNox theater. If row names are supplied of length one and the data \n    frame has a single row, the row.names is taken. To specify the row names and not a column. By name or number. : \n    If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify \n    the row names and not a column (by name or number) Can we go : Please
3      There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). \n    If row names are supplied of length one. : And the data frame has a single row, the row.names is taken to specify \n    the row names and not a column (by name or number) Can we go : Please
+3

Rizwan, , , . , (, row.names - , OP, , row.names 3 2 ). , / , OP, . Rizwan's.

1: , "" /, .

2:. PCRE , , ( : if/else, )

,

^(?(?!(?:[^:\v]*?\.\h){3,})([^:\v]*?)\s*:\s*|)(.*)$


There is a horror movie running in the iNox theater. : If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please

There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken. To specify the row names and not a column. By name or number. : If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please

There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). If row names are supplied of length one. : And the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please

1

  • 1: There is a horror movie running in the iNox theater.
  • 2: If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please

2

  • 1: -
  • 2: There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken. To specify the row names and not a column. By name or number. : If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please

3

  • 1: -
  • 2: There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). If row names are supplied of length one. : And the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please

  • ^
  • (?(?!(?:[^:\v]*?\.\h){3,})([^:\v]*?)\s*:\s*|)
    • (?(?!...)x|y) (?!...)
      • (?:[^:\v]*?\.\h){3,} 3
      • [^:\v]*? , ( ) ,
      • \.\h , ( )
      • : ,
      • ([^:\v]*?)\s*:\s*
        • ([^:\v]*?) 1: , ( ) ,
        • \s*:\s* , , ( , * +, , / , "" :)
      • false: , :
  • (.*) 2: ( , s )
  • $
+3

. :

library(stringr)

# throw out everything after first :, and count the number of sentences
split = str_count(sub(':.*', '', df$Text), fixed('. ')) < 3

# assemble the required data (you could also avoid ifelse if really needed)
data.frame(col1 = ifelse(split, sub(':.*', '', df$Text), NA),
           col2 = ifelse(split, sub('.*?:', '', df$Text), df$Text))
+2

; grep, : , :

sp <- strsplit(x, '(?<=\\.)(?=\\s+\\S)', perl = TRUE)[[1L]]
sp <- if (grep(':', sp)[1L] < 3L)
  sub(':\\s+', '$', x) else paste0('$', x)
sp <- gsub('\\v', '', sp, perl = TRUE)

str(read.table(text = sp, sep = '$', col.names = paste0('Col', 1:2), as.is = TRUE))

# 'data.frame': 1 obs. of  2 variables:
#   $ Col1: chr "There is a horror movie running in the iNox theater. "
#   $ Col2: chr "If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names an"| __truncated__

, :

For example, you can use different punctuation to signal the end of a sentence (for example, it end_of_sentence = '.!?)'will split the text into sentences if one of them is .!?)followed by a space); nallows you to control the number of sentences to search for the first :; and you can change sepif you expect $in your text (select the character here that most likely will not be in your text)

f <- function(text, end_of_sentence = '.', n = 3L, sep = '$') {
  p <- sprintf('(?<=[%s])(?=\\s+\\S)', end_of_sentence)

  sp <- strsplit(text, p, perl = TRUE)[[1L]]
  sp <- if (grep(':', sp)[1L] <= n)
    sub(':\\s+', sep, text) else paste0(sep, text)
  sp <- trimws(gsub('\\v', '', sp, perl = TRUE))

  read.table(text = sp, sep = sep, col.names = paste0('Col', 1:2),
             stringsAsFactors = FALSE)
}

## test
f(x); f(y); f(z)

## vectorize it to work on more than one string
f <- Vectorize(f, SIMPLIFY = FALSE, USE.NAMES = FALSE)

do.call('rbind', f(df$Text))

#   Col1
# 1 There is a horror movie running in the iNox theater. 
# 2                                                  <NA>
# 3                                                  <NA>
#   Col2
# 1 If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please
# 2 There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken. To specify the row names and not a column. By name or number. : If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please
# 3 There is a horror movie running in the iNox theater. If row names are supplied of length one and the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number). If row names are supplied of length one. : And the data frame has a single row, the row.names is taken to specify the row names and not a column (by name or number) Can we go : Please
+1
source

Source: https://habr.com/ru/post/1686287/

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