如何返回带有逻辑列的数据框,这些列表示字符串是否出现在列中？

Question

我有一个我希望搜索的3列数据框.我有一个我想在每列中搜索的字符串列表.我想返回一个包含原始数据的数据帧,以及一个字符串列表中每个字符串的列,以及是否在该行的列中找到该字符串的指示符.

这是一个近似我的数据的简化版本.

strings <- c("ape", "bear", "cat", "dog")

# A tibble: 7 x 3
                   snippet          headline       abstract
                     <chr>             <chr>          <chr>
1           this is an ape            An ape    some random
2           blah blah blah            An ape    some random
3 this is some random text  some random text some ape stuff
4           this is a bear    this is a bear      bear time
5            some cat text         bear time       dog time
6         cat and dog text         blah blah           blah
7           blah blah blah this is just text           blah

输出输出(df):

dput(df)
structure(list(snippet = c("this is an ape", "blah blah blah", 
"this is some random text", "this is a bear", "some cat text", 
"cat and dog text", "blah blah blah"), headline = c("An ape", 
"An ape", "some random text", "this is a bear", "bear time", 
"blah blah", "this is just text"), abstract = c("some random", 
"some random", "some ape stuff", "bear time", "dog time", "blah", 
"blah")), .Names = c("snippet", "headline", "abstract"), class = c("tbl_df", 
"tbl", "data.frame"), row.names = c(NA, -7L))

我希望它返回类似下面的数据帧

# A tibble: 7 x 7
                   snippet          headline       abstract   ape  bear   cat   dog
                     <chr>             <chr>          <chr> <lgl> <lgl> <lgl> <lgl>
1           this is an ape            An ape    some random  TRUE FALSE FALSE FALSE
2           blah blah blah            An ape    some random  TRUE FALSE FALSE FALSE
3 this is some random text  some random text some ape stuff  TRUE FALSE FALSE FALSE
4           this is a bear    this is a bear      bear time FALSE  TRUE FALSE FALSE
5            some cat text         bear time       dog time FALSE  TRUE  TRUE FALSE
6         cat and dog text         blah blah           blah FALSE FALSE  TRUE  TRUE
7           blah blah blah this is just text           blah FALSE FALSE FALSE FALSE

我已经使用grepl来返回所需的行,但显然有更好的方法来执行此操作并跟踪哪个字符串正在命中哪一行

预先感谢您的帮助

Answer 1

由于您不需要指定找到字符串的列,您可以将每行折叠为单个字符串列,并在其中搜索/ grepl

就像是

strings <- c("ape", "bear", "cat", "dog")

df$colStrings <- with(df, paste(snippet, headline, abstract, sep = ","))

sapply(strings, function(x) grepl(x, df$colStrings))

#        ape  bear   cat   dog
# [1,]  TRUE FALSE FALSE FALSE
# [2,]  TRUE FALSE FALSE FALSE
# [3,]  TRUE FALSE FALSE FALSE
# [4,] FALSE  TRUE FALSE FALSE
# [5,] FALSE  TRUE  TRUE  TRUE
# [6,] FALSE FALSE  TRUE  TRUE
# [7,] FALSE FALSE FALSE FALSE