如何将数据框类别描述为 r-markdown pdf 中的部分和内容?

How to describe dataframe category into section and content in r-markdown pdf?

df

Id  Section       Comment
------------------------------------------------------------
1   Product A   this is the general comment for product A
2   Product A   this is the general comment for product A
3   Product A   this is the general comment for product A
4   Product B   this is the general comment for product B
5   Product B   this is the general comment for product B
8   Product C   this is the general comment for product C
9   Product C   this is the general comment for product C
10  Product C   this is the general comment for product C

上面的是我的数据框。我正在寻找类似这样的输出

expected output:
------------------
Product A
this is the general comment for product A
this is the general comment for product A

Product B
this is the general comment for product B
this is the general comment for product B

如果我以这种方式遍历每一行我得到 section and comment section and comment

我尝试使用基于部分的索引,如下面的代码

我的代码

section_df<-df%>%select("Section")%>% dplyr::mutate(r_number = row_number()) %>%
group_by(`Section`) %>%
dplyr::summarise(index = min(r_number))

section_df<-section_df[order(section_df$index),]

for(i in 1:nrow(df)){
  if(section_df$index[i] == i){
    
    cat(df$Section[i])
    cat(df$Comment[i])

  }else{
    cat(df$Comment[i])
  }
  
}
section_df<-section_df[complete.cases(section_df), ]

for(i in 1:nrow(df)){
  
  if(i %in% section_df$index){
    print(df$Section[i])
  }
  else{
    print(df$Comment[i])
  }

}