删除 R 中另一列中存在的一列中的单词答案

【问题标题】：Remove words in one column present in another column in R删除 R 中另一列中存在的一列中的单词
【发布时间】：2018-10-01 14:49:39
【问题描述】：

我有一个采用这种格式的数据框：

A <- c("John Smith", "Red Shirt", "Family values are better")
B <- c("John is a very highly smart guy", "We tried the tea but didn't enjoy it at all", "Family is very important as it gives you values")

df <- as.data.frame(A, B)

我的目的是将结果返回为：

ID   A                           B
1    John Smith                  is a very highly smart guy
2    Red Shirt                   We tried the tea but didn't enjoy it at all
3    Family values are better    is very important as it gives you

我试过了：

test<-df %>% filter(sapply(1:nrow(.), function(i) grepl(A[i], B[i])))

但它并没有给我想要的东西。

有什么建议/帮助吗？

【问题讨论】：

标签： r regex dataframe

【解决方案1】：

一种解决方案是将mapply 与strsplit 一起使用。

诀窍是将df$A 拆分为单独的单词，然后折叠由| 分隔的单词，然后将其用作gsub 中的pattern 以替换为""。

lst <- strsplit(df$A, split = " ")

df$B <- mapply(function(x,y){gsub(paste0(x,collapse = "|"), "",df$B[y])},lst,1:length(lst))
df
# A                                           B
# 1               John Smith                  is a very highly smart guy
# 2                Red Shirt We tried the tea but didn't enjoy it at all
# 3 Family values are better          is very important as it gives you

另一种选择是：

df$B <- mapply(function(x,y)gsub(x,"",y) ,gsub(" ", "|",df$A),df$B)

数据：

A <- c("John Smith", "Red Shirt", "Family values are better")
B <- c("John is a very highly smart guy", "We tried the tea but didn't enjoy it at all", "Family is very important as it gives you values")

df <- data.frame(A, B, stringsAsFactors = FALSE)

【讨论】：

很好的答案@MKR，在我的情况下效果很好。在我的情况下，您的第二个选项工作得稍微快一些。我正在使用几百万行 data.frame。如果基于 data.table 的方法更省时，有什么线索吗？
通过切换$A 和$B 这对我有用。谢谢！如何仅删除不匹配的部分？

【解决方案2】：

使用stringr::str_split_fixed 函数的另一种选择：

library(stringr)

str_split_fixed(sapply(paste(df$A,df$B, sep=" columnbreaker "), 
                function(i){
                            paste(unique(
                                         strsplit(as.character(i), split=" ")[[1]]), 
                         collapse = " ")}), 
                 " columnbreaker ", 2)


#       [,1]                       [,2]                                         
# [1,] "John Smith"               "is a very highly smart guy"                 
# [2,] "Red Shirt"                "We tried the tea but didn't enjoy it at all"
# [3,] "Family values are better" "is very important as it gives you"

【讨论】：

这也成功了。谢谢你。虽然我觉得上面的解决方案更优雅，更适合我的需要（我有一个巨大的数据集）