Question

如何在字符串中的用户名后添加逗号，以便我可以消除逗号前的单词，以便获得可用于精确匹配的统一字符串。

 a=dataframe(text=c("hi john what are you doing",
                "hi sunil what are you doing",
                "hello sanjay what are you doing"),stringsAsFactors =FALSE)

Answer 1

如果您知道用户名在句子中位于第二位，则可以从DF中提取句子并使用它：

text=c("hi john what are you doing",
                "hi sunil what are you doing",
                "hello sanjay what are you doing")

for (sentence in text) {
  #separate words in sentence
  spl <- strsplit(sentence," ")
  #extract name and converto to uppercase
  name <- toupper(as.character(spl[[1]])[2])
  #put a comma after name
  name2 <- paste(name, ",", sep="")
  #replace original name with new one
  spl[[1]][2] <- name2
  #loop over the sentence words to recretae the sentence
  for ( i in 1:length(spl[[1]])-1 ) {
    if (i == 1) sentence2 <- paste(spl[[1]][i], spl[[1]][i+1])
    else sentence2 <- paste(sentence2, spl[[1]][i+1])
    }
    #put in new list (text2)
    if (sentence == text[1]) text2 <- c(sentence2)
    else text2 <- append( text2, sentence2 )
  }

结果：

#text2
#[1] "hi JOHN, what are you doing"      "hi SUNIL, what are you doing"    
#[3] "hello SANJAY, what are you doing"

然后重新创建数据框。

否则，如果您的用户名在句子中的位置可能有所不同，但是您有需要查找的用户名列表，则还可以检查是否找到至少一个用户名，将用户名在句子中的位置替换，替换，放入逗号，然后重新创建，或者如果找不到则打印错误。

usernames <- c("john", "sunil", "sanjay")

text=c("hi john what are you doing",
                "hi sunil what are you doing",
                "hello sanjay what are you doing",
                "hello ciao how are you"
              )


for (sentence in text) {

  user_present <- NA

  #separate words in sentence
  spl <- strsplit(sentence," ")

  #check if a user is present in the sentence
  for (user in usernames) {
    if ( user %in% spl[[1]]) {
      user_present <- user
      break
    }}

  #if at least one user is found
  if ( !is.na(user_present) ) {
    pos <-   which( spl[[1]] == user_present )
    #extract name and converto to uppercase
    name <- toupper(as.character(spl[[1]])[pos])
    #put a comma after name
    name2 <- paste(name, ",", sep="")
    #replace original name with new one
    spl[[1]][2] <- name2
    #loop over the sentence words to recretae the sentence
    for ( i in 1:length(spl[[1]])-1 ) {
      if (i == 0) sentence2 <- paste(spl[[1]][i], spl[[1]][i+1])
      else sentence2 <- paste(sentence2, spl[[1]][i+1])
      }
      #put in new list (text2)
      if (sentence == text[1]) text2 <- c(sentence2)
      else text2 <- append( text2, sentence2 )
  #if NO username in sentence
  } else {
    #print error message with username and sentence in which not found
    err.msg <- paste("NO username found in sentence: ", sentence)
    print(err.msg)
  }
}

结果：

#[1] "NO username found in sentence:  hello ciao how are you"

text2
#[1] " hi JOHN, what are you doing"      " hi SUNIL, what are you doing"    
#[3] " hello SANJAY, what are you doing"

希望有帮助！

###END

Answer 2

两个解决方案。

首先，如果您可以获取包含用户名的列表。

usernames <- c("john", "sunil", "sanjay")
diag(sapply(usernames, function(x) gsub(x, paste0(x, ","), a$text)))
# [1] "hi john, what are you doing"      "hi sunil, what are you doing"     "hello sanjay, what are you doing"

或者，如果用户名始终是第二个单词。

gsub("(^\\w*\\s)(\\w*)", "\\1\\2,", a$text)
# [1] "hi john, what are you doing"      "hi sunil, what are you doing"     "hello sanjay, what are you doing"

数据

a <- structure(list(text = c("hi john what are you doing", "hi sunil what are you doing", 
"hello sanjay what are you doing")), class = "data.frame", row.names = c(NA, 
-3L))

使用R在数据框中的人名后添加逗号

2 个答案: