在R中的列中搜索多个值答案

【问题标题】：Search for multiple values in a column in R在R中的列中搜索多个值
【发布时间】：2019-01-20 14:01:06
【问题描述】：

我有一个包含两列的数据框：

df = data.frame(animals = c("cat; dog; bird", "dog; bird", "bird"), sentences = c("the cat is brown; the dog is barking; the bird is green and blue","the dog is black; the bird is yellow and blue", "the bird is blue"), stringsAsFactors = F)

我需要整个“句子”列中每一行所有“动物”出现的总和。

例如：“animals”第一行 c("cat;dog;bird") = sum_occurrences_sentences_column (cat = 1) + (dog = 2) + (bird = 3) = 6 。

结果将是这样的第三列：

df <- cbind( sum_accurrences_sentences_column = c("6", "5", "3"), df)

我尝试了以下代码，但它们不起作用。

df[str_split(df$animals, ";") %in% df$sentences, ]

str_count(df$sentences, str_split(df$animals, ";"))

任何帮助将不胜感激:)

【问题讨论】：

标签： r stringr

【解决方案1】：

这是一个基本的R 解决方案：

先把;和gsub全部去掉，然后把句子列和unlist拆分成一个向量：

split_sentence_column = unlist(strsplit(gsub(';','',df$sentences),' '))

然后设置一个 for 循环，为每一行获取一个动物向量，用%in%检查动物列表中的哪个句子列动物，然后对所有TRUE案例求和。然后我们可以直接将它分配给一个新的 df 列：

for(i in 1:nrow(df)){
  animals = unlist(strsplit(df$animals[i], '; '))
  df$sum_occurrences_sentences_column[i] = sum(split_sentence_column %in% animals)
}

> df
         animals                                                        sentences sum_occurrences_sentences_column
1 cat; dog; bird the cat is brown; the dog is barking; the bird is green and blue                                6
2      dog; bird                    the dog is black; the bird is yellow and blue                                5
3           bird                                                 the bird is blue                                3

【讨论】：

【解决方案2】：

一种map() 操作第一列中每个动物块的方法。

library(tidyverse)
string <- unlist(str_split(df$sentences, ";"))

df %>% rowwise %>%
  mutate(SUM = str_split(animals, "; ", simplify = T) %>%
    map( ~ str_count(string, .)) %>%
    unlist %>% sum)

#   animals        sentences                                           SUM
#   <chr>          <chr>                                               <int>
# 1 cat; dog; bird the cat is brown; the dog is barking; the bird...   6
# 2 dog; bird      the dog is black; the bird is yellow and blue       5
# 3 bird           the bird is blue                                    3

【讨论】：