R粘贴带标题的html字符串

Question

找不到可能非常简单的问题的令人满意的解决方案。

我有一个数据框

df <- data.frame(date=c("a","a","a","a","b","b"),text=c("c","d","e","f","g","h"))

而且我需要这样的字符串：

"<h4>date a </h4><br> c <br> d <br> e <br> f <br> <h4>date b </h4> <br> g <br> h"

任何提示都会非常感激

Answer 1

有点笨拙，但您可以尝试：

do.call(paste, list("<h4> date", unique(df$date), "</h4><br>",  tapply(df$text, df$date, FUN =  paste, collapse = " <br> "), collapse = " "))

[1] "<h4> date a </h4><br> c <br> d <br> e <br> f <br> <h4> date b </h4><br> g <br> h"

Answer 2

类似这样的东西：

 df <- data.frame(date=c("a","a","a","a","b","b"),text=c("c","d","e","f","g","h"), stringsAsFactors = F)


 p1 <- paste("<h4>date", unique(df$date)[1], "</h4><br>", paste(df$text[df$date=="a"], collapse = " <br> "), "<br>")
 p2 <- paste("<h4>date", unique(df$date)[2], "</h4><br>", paste(df$text[df$date=="b"], collapse = " <br> "))

 paste(p1,p2)