使用 grep 标记文本并在 r 中粘贴

Question

我有两个数据框。第一个：

keyword <- c("apple","peach","grape","berry","kiwi fruit")
keyword <- data.frame(keyword)

第二个：

sentence <- c("I like apple","I hate apple","grape is good")
url <- c("url1","url2","url3")
sentence <- data.frame(sentence,url)

我需要做的是：如果句子中有关键字，就把url粘贴到正文中。如果多个句子包含关键字，则粘贴所有url。最终结果是这样的：

我尝试使用下面的代码，但没有按预期运行。

keyword$Label <- character(length(keyword$keyword))

for (i in 1:length(keyword$keyword)) {
keyword$Label[grep(keyword$keyword[i],sentence$sentence)] <- sentence$url
}

Answer 1

stringr+dplyr+tidyr的解决方案：

library(stringr)
library(dplyr)
library(tidyr)

sentence %>%
  mutate(sentence = str_extract(sentence, paste0(keyword$keyword, collapse = "|"))) %>%
  right_join(keyword, by = c("sentence" = "keyword")) %>%
  group_by(sentence) %>%
  mutate(URL = 1:n()) %>%
  spread(URL, url, sep = "") %>%
  rename(keyword = sentence)

结果：

# A tibble: 5 x 3
# Groups:   keyword [5]
     keyword  URL1  URL2
*      <chr> <chr> <chr>
1      apple  url1  url2
2      berry  <NA>  <NA>
3      grape  url3  <NA>
4 kiwi fruit  <NA>  <NA>
5      peach  <NA>  <NA>

数据：

keyword <- c("apple","peach","grape","berry","kiwi fruit")
keyword <- data.frame(keyword, stringsAsFactors = FALSE)
sentence <- c("I like apple","I hate apple","grape is good")
url <- c("url1","url2","url3")
sentence <- data.frame(sentence,url, stringsAsFactors = FALSE)

使用 grep 标记文本并在 r 中粘贴

Tag text using grep and paste in r

text

r

data-manipulation

text-mining

dataframe