R 如何插入字符串以使每一行具有相同的模式

这是一张follow up question美元的.如何在_之间添加n个空字符串，以使每行都有exactly个10个单词，每个单词由_分隔？

• 数据为:

> head(dfLong, 10)
# A tibble: 5 x 1
  word                                                                           
  <chr>                                                                          
1 Jason_Oscar_Maleeka_Janet_Gabriel_Raheema_Bryce_Nasreen_Hishaam_Thadduse       
2 Marcos_Daijah_Chassity_Carlito_Chidiebere_Matthew_Maureene_Jillian_Markus_Aaron
3 Ramziyya_Marquez_Kiera_Farajallah_Larisa_Davier_Shujaa_Vincent_Orlando_Joseph  
4 Desean_Chelsea_Faadil_Christopher_Aarifa_Joel_Matthew_Jacob_Aeones_Matthew     
5 Jacob_Savannah_Nadia_Kaleem    ### THIS IS WHAT I NEED TO CHANGE                                                
> 

• 请注意，情况并非如此.

1 Jason_Oscar_Maleeka_Janet_Gabriel_Raheema_Bryce_Nasreen_Hishaam_Thadduse       
2 Marcos_Daijah_Chassity_Carlito_Chidiebere_Matthew_Maureene_Jillian_Markus_Aaron
3 Ramziyya_Marquez_Kiera_Farajallah_Larisa_Davier_Shujaa_Vincent_Orlando_Joseph  
4 Desean_Chelsea_Faadil_Christopher_Aarifa_Joel_Matthew_Jacob_Aeones_Matthew     
5 Jacob_Savannah_Nadia_Kaleem_''_''_''_''_''_''   ## LIKE THIS 

Questions:

1:我需要每一行都有exatcly个10个单词.在字数不能被10整除的情况下，我想在_之间插入空字符串，如下所示:_‘’_.tidyverse和stringr解决方案将不胜感激！谢谢！

2:稍后，我还需要另一个DF，其中所有行都合并到一个新的单元格中.This answer人帮了我.但是，在合并行之前，我需要确保每行恰好有10个单词(稍后，我将使用JS split('_').slice(v,v+10).join("<br>"))在UI中显示该数据的每10个单词，我将把它们拆分为10个单词，然后一个接一个地显示).先谢谢你.

• 生效日期:

dput(df)
structure(list(word = c("Jason_Oscar_Maleeka_Janet_Gabriel_Raheema_Bryce_Nasreen_Hishaam_Thadduse", 
"Marcos_Daijah_Chassity_Carlito_Chidiebere_Matthew_Maureene_Jillian_Markus_Aaron", 
"Ramziyya_Marquez_Kiera_Farajallah_Larisa_Davier_Shujaa_Vincent_Orlando_Joseph", 
"Desean_Chelsea_Faadil_Christopher_Aarifa_Joel_Matthew_Jacob_Aeones_Matthew", 
"Jacob_Savannah_Nadia_Kaleem")), row.names = c(NA, -5L), class = c("tbl_df", 
"tbl", "data.frame"))