如何计算R中数据框中提到的列表中的单词数答案

【问题标题】：How do I count the number of words from a list mentioned in a data frame in R如何计算R中数据框中提到的列表中的单词数
【发布时间】：2019-12-19 03:31:34
【问题描述】：

我有一个包含多行评论和文本列的数据框。我还有一个包含单词的列表。我想要一个 for 循环来检查数据帧的每一行，以总结从列表中找到的单词数。我想保持每行总和由行分隔并将结果放入新的结果数据框中。

#Data Frame
Review           Text
1           I like to run and play.
2           I eat cookies.
3           I went to swim in the pool.
4           I like to sleep.
5           I like to run, play, swim, and eat.

#List Words
Run
Play
Eat
Swim

#Result Data Frame
Review      Count
1            2
2            1
3            1
4            0
5            4

【问题讨论】：

标签： r dataframe count apply

【解决方案1】：

这是base R 的解决方案，其中gregexpr 用于计算出现次数。

给定如下模式

pat <- c("Run", "Play", "Eat", "Swim")

那么添加到数据框的计数可以通过以下方式进行：

df$Count <- sapply(gregexpr(paste0(tolower(pat),collapse = "|"),tolower(df$Text)), 
                   function(v) ifelse(-1 %in% v, 0,length(v)))

这样

> df
  Review                                Text Count
1      1              I like to run and play     2
2      2                       I eat cookies     1
3      3         I went to swim in the pool.     1
4      4                    I like to sleep.     0
5      5 I like to run, play, swim, and eat.     4

【讨论】：

【解决方案2】：

我们可以在将words 粘贴在一起作为一个模式之后使用stringr::str_count。

df$Count <- stringr::str_count(df$Text, 
                   paste0("\\b", tolower(words), "\\b", collapse = "|"))

df
#  Review                                Text Count
#1      1             I like to run and play.     2
#2      2                      I eat cookies.     1
#3      3         I went to swim in the pool.     1
#4      4                    I like to sleep.     0
#5      5 I like to run, play, swim, and eat.     4

数据

df <- structure(list(Review = 1:5, Text = structure(c(2L, 1L, 5L, 4L, 
3L), .Label = c("I eat cookies.", "I like to run and play.", 
"I like to run, play, swim, and eat.", "I like to sleep.", 
"I went to swim in the pool."), class = "factor")), class = 
"data.frame", row.names = c(NA, -5L))
words <- c("Run","Play","Eat","Swim")

【讨论】：

有没有办法创建一个循环来循环遍历数据框和列表？上面的数据框和单词列表就是一个例子。我正在使用的数据框包含 600 条评论，列表包含大约 40 个单词。
@JaylonAaron 没关系。这应该仍然有效。您的单词列表是如何存储的？
我让它工作了。我必须先取消列表中的单词，然后再运行它。感谢您的帮助！
@JaylonAaron 如果您觉得它对您有用，请点击投票按钮旁边的复选标记，随时accept the answer。 :-) 每个帖子只能接受一个答案。

【解决方案3】：

Base R 解决方案（注意此解决方案有意不区分大小写）：

# Create a vector of patterns to search for: 

patterns <- c("Run", "Play", "Eat", "Swim")

# Split on the review number, apply a term counting function (for each review number): 

df$term_count <- sapply(split(df, df$Review), 

                        function(x){length(grep(paste0(tolower(patterns), collapse = "|"),

                               tolower(unlist(strsplit(x$Text, "\\s+")))))})

数据：

df <- data.frame(Review = 1:5, Text = as.character(c("I like to run and play",
                                                     "I eat cookies",
                                                     "I went to swim in the pool.",
                                                     "I like to sleep.", 
                                                     "I like to run, play, swim, and eat.")), 
                 stringsAsFactors = FALSE)

【讨论】：