match_fun为%的fuzzy_left_join

Question

一些数据

example_df <- data.frame(
  url = c('blog/blah', 'blog/?utm_medium=foo', 'blah', 'subscription/apples', 'UK/something'),
  numbs = 1:5
)

lookup_df <- data.frame(
  string = c('blog', 'subscription', 'UK'),
  group = c('blog', 'subs', 'UK')
)


library(fuzzyjoin)
data_combined <- example_df %>% 
  fuzzy_left_join(lookup_df, by = c("url" = "string"), 
                  match_fun = `%in%`)

data_combined
                   url numbs string group
1            blog/blah     1   <NA>  <NA>
2 blog/?utm_medium=foo     2   <NA>  <NA>
3                 blah     3   <NA>  <NA>
4  subscription/apples     4   <NA>  <NA>
5         UK/something     5   <NA>  <NA>

我希望data_combined有字符串和组的值，其中有基于match_fun的匹配项。取而代之的是所有的NA。

例如，lookup_df中字符串的第一个值是'blog‘。由于这是博客字符串的第一个值，因此应与字符串和组字段中的值‘%in%’和‘example_df’匹配。

Answer 1

如果我们想要与'url‘中的字符串之前的单词与'lookup_df’中的‘/’列进行部分匹配，我们可以提取该子字符串作为新列，然后执行regex_left_join

library(dplyr)
library(fuzzyjoin)
library(stringr)
example_df %>%
    mutate(string = str_remove(url, "\\/.*")) %>% 
    regex_left_join(lookup_df, by = 'string') %>%
    select(url, numbs, group)

-output

#                   url numbs group
#1            blog/blah     1  blog
#2 blog/?utm_medium=foo     2  blog
#3                 blah     3  <NA>
#4  subscription/apples     4  subs
#5         UK/something     5    UK