如何基于字符串模式创建新的urls

Question

df <- data.frame(url c("https://tapatalk.com/groups/thee-t119532-s0.html?sid=674002291c431ba23dd69c34e8a20217",
      "https://tapatalk.com/groups/thee-t119532-s50.html?sid=674002291c431ba23dd69c34e8a20217",
      "https://tapatalk.com/groups/thee-t119532-s60.html?sid=674002291c431ba23dd69c34e8a20217",
      "https://tapatalk.com/groups/thee-t119532-s70.html?sid=674002291c431ba23dd69c34e8a20217","https://tapatalk.com/groups/thee-t143332-s0.html?sid=674002291c431ba23dd69c34e8a20217",
      "https://tapatalk.com/groups/thee-t143332-s30.html?sid=674002291c431ba23dd69c34e8a20217"),
    page_id=c("0","50","60","70","0","30"))

我有一组带有子页面的URL。子页面遵循模式s-0是第一个子页s-10是第二个，然后是s-20、s-30等等。有许多子页面的URL，我只有第一个和最后一个子页面编号。例如，我可能有s-0和s-70，但没有从s-10到s-60。我想要的是每个URL都有一个子页面标识符。

例如，从上面的数据框架中，我想检索

df <- data.frame(url = c("https://tapatalk.com/groups/thee-t119532-s0.html?sid=674002291c431ba23dd69c34e8a20217",
"https://tapatalk.com/groups/thee-t119532-s10.html?sid=674002291c431ba23dd69c34e8a20217"),
"https://tapatalk.com/groups/thee-t119532-s0.html?sid=674002291c431ba23dd69c34e8a20217",
"https://tapatalk.com/groups/thee-t119532-s30.html?sid=674002291c431ba23dd69c34e8a20217",
"https://tapatalk.com/groups/thee-t119532-s40.html?sid=674002291c431ba23dd69c34e8a20217",
"https://tapatalk.com/groups/thee-t119532-s50.html?sid=674002291c431ba23dd69c34e8a20217",
"https://tapatalk.com/groups/thee-t119532-s60.html?sid=674002291c431ba23dd69c34e8a20217",
"https://tapatalk.com/groups/thee-t119532-s70.html?sid=674002291c431ba23dd69c34e8a20217",
"https://tapatalk.com/groups/thee-t143332-s0.html?sid=674002291c431ba23dd69c34e8a20217",
"https://tapatalk.com/groups/thee-t143332-s10.html?sid=674002291c431ba23dd69c34e8a20217",
"https://tapatalk.com/groups/thee-t143332-s20.html?sid=674002291c431ba23dd69c34e8a20217",
      "https://tapatalk.com/groups/thee-t143332-s30.html?sid=674002291c431ba23dd69c34e8a20217"),
page_id=c("0","10","20","30","40","50","60","70","0","10","20","30"))

我已经分离出URL的末尾，并创建了一个具有最大子页面标识符的列，但我不确定还能去哪里。

Answer 1

使用regex将页面id和其他url组件拆分为带有tidyr::extract()的单独列；在分组摘要中使用tidyr::full_seq()填充中间的页id；然后将这些列重新组合在一起。

library(tidyr)
library(dplyr)

df %>%
  extract(
    url, 
    into = c("url1", "page_id", "url2"),
    "(.+-s)(\\d+)(\\.html.*)"
  ) %>%
  group_by(url1, url2) %>%
  summarize(page_id = full_seq(as.numeric(page_id), 10), .groups = "drop") %>%
  unite("url", url1, page_id, url2, sep = "")

# A tibble: 12 × 1
   url                                                                          
   <chr>                                                                        
 1 https://tapatalk.com/groups/thee-t119532-s0.html?sid=674002291c431ba23dd69c3…
 2 https://tapatalk.com/groups/thee-t119532-s10.html?sid=674002291c431ba23dd69c…
 3 https://tapatalk.com/groups/thee-t119532-s20.html?sid=674002291c431ba23dd69c…
 4 https://tapatalk.com/groups/thee-t119532-s30.html?sid=674002291c431ba23dd69c…
 5 https://tapatalk.com/groups/thee-t119532-s40.html?sid=674002291c431ba23dd69c…
 6 https://tapatalk.com/groups/thee-t119532-s50.html?sid=674002291c431ba23dd69c…
 7 https://tapatalk.com/groups/thee-t119532-s60.html?sid=674002291c431ba23dd69c…
 8 https://tapatalk.com/groups/thee-t119532-s70.html?sid=674002291c431ba23dd69c…
 9 https://tapatalk.com/groups/thee-t143332-s0.html?sid=674002291c431ba23dd69c3…
10 https://tapatalk.com/groups/thee-t143332-s10.html?sid=674002291c431ba23dd69c…
11 https://tapatalk.com/groups/thee-t143332-s20.html?sid=674002291c431ba23dd69c…
12 https://tapatalk.com/groups/thee-t143332-s30.html?sid=674002291c431ba23dd69c…