r - 将txt文件加载到R中并根据其他数据框替换一些值

Question

我有一个包含特定格式结构的大型 txt 文件。我的目标是使用 readLines 在 R 中加载文本，我想根据我的 df 数据框用新值替换每条记录的权重值。我不想更改 .txt 数据结构格式或解析 .txt 文件。最终输出应具有与原始 .txt (writeLines()) 完全相同的结构。我如何读取它并更新值？谢谢

这是我的引用数据框

df <- tibble::tribble(
        ~House_id,  ~id, ~new_weight,
  18105265, "Mab",        4567,
  18117631, "Maa",        3367,
  18121405, "Mab",        4500,
  71811763, "Maa",        2455,
  71811763, "Mab",        2872
  ) 

这是我的 .txt 的一小部分

H18105265_0
R1_0
Mab_3416311514210525745_W923650.80
T1_0
T2_0
T3_0
V64_0_2_010_ab171900171959
H18117631_0
R1_0
Maa_1240111711220682016_W123650.80
T1_0
V74_0_1_010_aa081200081259_aa081600081859_aa082100095659_aa095700101159_aa101300105059
H18121405_0
R1_0
Mab_2467211713110643835_W923650.80
T1_0
T2_0
V62_0_1_010_090500092459_100500101059_101100101659_140700140859_141100141359
H71811763_0
R1_0
Maa_5325411210120486554_W923650.80
Mab_5325411210110485554_W723650.80
T1_0
T2_0
T3_0
T4_0

此处是第一条个人记录 house_id = 18105265 的期望输出:更新 Mab_3416311514210525745_W923650.80 符合 df

的新值 Mab_3416311514210525745_W4567 基数

H18105265_0
R1_0
Mab_3416311514210525745_W4567
T1_0
T2_0
T3_0
V64_0_2_010_ab171900171959

Answer 1

编辑 - 添加 id 以查找以区分非唯一的 House_id。

这是一种方法，我读取数据，加入 df 中的更新权重，然后使用新权重在以“M”开头的行上创建更新值。

library(tidyverse)
read_fwf("txt_sample.txt" ,  col_positions = fwf_empty("txt_sample.txt")) %>% # edit suggested by DanG

# if the row starts with H, extract 8 digit house number and
# use that to join to the table with new weights
mutate(House_id = if_else(str_starts(X1, "H"), as.numeric(str_sub(X1, 2,9)), NA_real_),
       id = if_else(str_starts(X1, "M"), str_sub(X1, 1,3), NA_character_)) %>%
fill(House_id) %>%
left_join(df, by = c("House_id", "id")) %>%
fill(new_weight) %>%

# make new string using updated weight (or keep existing string)
mutate(X1_new = coalesce(
  if_else(str_starts(X1, "M"),
          paste0(word(X1, end = 2, sep = "_"), "_W", new_weight),
          NA_character_),
  X1)) %>%

pull(X1_new) %>% 
writeLines()

输出

H18105265_0
R1_0
Mab_3416311514210525745_W4567
T1_0
T2_0
T3_0
V64_0_2_010_ab171900171959
H18117631_0
R1_0
Maa_1240111711220682016_W3367
T1_0
V74_0_1_010_aa081200081259_aa081600081859_aa082100095659_aa095700101159_aa101300105059
H18121405_0
R1_0
Mab_2467211713110643835_W4500
T1_0
T2_0
V62_0_1_010_090500092459_100500101059_101100101659_140700140859_141100141359
H71811763_0
R1_0
Maa_5325411210120486554_W2455
Mab_5325411210110485554_W2872
T1_0
T2_0
T3_0
T4_0