如何用tidyverse/stringr插入空字符串使每行含10个_分隔词

• 如何为数据框的word列每行补充_''_格式的空字符串，让每行恰好包含10个用_分隔的元素？优先采用tidyverse/stringr方案。
• 将所有行合并到单个单元格中，合并前需保证每行已有10个元素，以便后续通过JS代码split('_').slice(v,v+10).join("<br>")按10个元素拆分展示。

数据示例：

> 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    ### 需要修改的行

期望输出：

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_''_''_''_''_''_''   ## 示例格式

数据结构：

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"))

步骤1：补充空字符串至每行10个元素 #

利用tidyverse的dplyr和stringr工具，先拆分字符串统计元素数量，再计算需补充的空字符串数量，最后完成拼接：

library(tidyverse)

# 加载数据
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"))

# 处理每行，补充空字符串
df_processed <- df %>%
  mutate(
    # 拆分字符串为元素列表
    word_list = str_split(word, "_"),
    # 统计当前元素数量
    count = map_int(word_list, length),
    # 计算需要补充的空字符串数量
    add_num = 10 - count,
    # 生成待补充的字符串片段（add_num为0时返回空）
    add_str = if_else(add_num > 0, str_c(rep("_''", add_num), collapse = ""), ""),
    # 拼接原字符串与补充片段
    word_10 = str_c(word, add_str)
  ) %>%
  select(word_10)

处理后结果：

df_processed
#> # A tibble: 5 × 1
#>   word_10                                                                        
#>   <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_''_''_''_''_''_''

步骤2：合并所有行到单个单元格 #

用str_c将处理后的所有行合并为连续的_分隔字符串，适配后续JS处理逻辑：

merged_str <- df_processed %>%
  pull(word_10) %>%
  str_c(collapse = "_")

合并后的字符串可直接用于JS代码：

// v为起始索引，按10个元素拆分并换行展示
const splitArr = merged_str.split('_').slice(v, v+10).join("<br>");

内容的提问来源于stack exchange，提问作者Larissa Cury