在R中的if语句之后将每个第n个文件保存到一个新的子文件夹中

Question

首先，如果这个问题已经在其他地方得到解决但我找不到答案，我们深表歉意。

在R 中，我有一个for loop，它根据特定条件将文本（writeLines）保存到文件中。我想将每 10 个写入的文件保存到一个新的不同子文件夹中。这样每个子文件夹最多只能有10个文件。

现在，如果要写入所有文件，我可以编写一个脚本来执行此操作（见下文），但我不确定每次文件夹已满 10 个文件时如何实现子文件夹的更改。

下面的例子应该澄清一下。

# generate random num
set.seed(15)
input <- rnorm(100, mean = 10, sd = 3)
# Write to file only if num is greater than threshold
thrshld <- 10
out_dir <- "~/R/tmp/Batch_Saving"

k <- 1
i <- 1
for (i in 1:length(input)) {

  if ( any(i == seq(from = 1, to = length(input), by = 10) ) ) {

    # Create a new subfolder everytime i is a multiple of 10
    sub_dir <- paste0(out_dir, "/Dir_Num_", k) 
    k <- k+1

  } 

  if ( input[i] > thrshld) {

    txt <- paste("The number", signif(input[i], 4), "is greater than", thrshld)

    # Create folder if it doesn't exist
    if (!dir.exists(sub_dir)) { dir.create(sub_dir, recursive = T) }

    # Write text to file
    writeLines(text = txt,
               con = paste0(sub_dir, "/file_", i, ".txt") )

  }

}

此脚本创建 10 个文件夹，每个文件夹少于 10 个文件，但文件数量不同。可以像这样在终端中快速检查：

Batch_Saving > find . -maxdepth 1 -mindepth 1 -type d -exec sh -c 'echo "{} : $(find "{}" -type f | wc -l)" file\(s\)' \;

./Dir_Num_4 :        6 file(s)
./Dir_Num_3 :        7 file(s)
./Dir_Num_2 :        4 file(s)
./Dir_Num_5 :        7 file(s)
./Dir_Num_10 :        4 file(s)
./Dir_Num_9 :        5 file(s)
./Dir_Num_7 :        3 file(s)
./Dir_Num_6 :        6 file(s)
./Dir_Num_1 :        6 file(s)
./Dir_Num_8 :        4 file(s)

我相信实现这一点的唯一方法是每次读取已经写入了多少文件，或者以某种方式跟踪已经写入了多少文件并相应地更改参数k。

我相信这也可以通过其他方法（即apply）实现，但为了学习，我想在循环中编写代码。

非常感谢！

Answer 1

尝试将k 循环嵌套在i 循环内创建子目录以进行阈值检查，如下所示：

for (i in 1:length(input)) {
  if (input[i] > thrshld) {
    if ( k %in% seq(from = 1, to = length(input), by = 10) ) {
      # Create a new subfolder everytime i is a multiple of 10
      sub_dir <- paste0(out_dir, "/Dir_Num_", k) 
    } 
    k <- k+1
#    
    txt <- paste("The number", signif(input[i], 4), "is greater than", thrshld)
#    
    # Create folder if it doesn't exist
    if (!dir.exists(sub_dir)) { dir.create(sub_dir, recursive = T) }
    # Write text to file
    writeLines(text = txt,
               con = paste0(sub_dir, "/file_", i, ".txt") )
  }
}

结果如下

> list.files("~/R/tmp", recursive = T)
 [1] "Dir_Num_1/file_1.txt"   "Dir_Num_1/file_11.txt"  "Dir_Num_1/file_13.txt"  "Dir_Num_1/file_15.txt" 
 [5] "Dir_Num_1/file_18.txt"  "Dir_Num_1/file_2.txt"   "Dir_Num_1/file_4.txt"   "Dir_Num_1/file_5.txt"  
 [9] "Dir_Num_1/file_7.txt"   "Dir_Num_1/file_8.txt"   "Dir_Num_11/file_21.txt" "Dir_Num_11/file_22.txt"
[13] "Dir_Num_11/file_25.txt" "Dir_Num_11/file_26.txt" "Dir_Num_11/file_27.txt" "Dir_Num_11/file_29.txt"
[17] "Dir_Num_11/file_30.txt" "Dir_Num_11/file_32.txt" "Dir_Num_11/file_33.txt" "Dir_Num_11/file_34.txt"
[21] "Dir_Num_21/file_35.txt" "Dir_Num_21/file_36.txt" "Dir_Num_21/file_38.txt" "Dir_Num_21/file_41.txt"
[25] "Dir_Num_21/file_42.txt" "Dir_Num_21/file_43.txt" "Dir_Num_21/file_46.txt" "Dir_Num_21/file_48.txt"
[29] "Dir_Num_21/file_49.txt" "Dir_Num_21/file_50.txt" "Dir_Num_31/file_51.txt" "Dir_Num_31/file_52.txt"
[33] "Dir_Num_31/file_54.txt" "Dir_Num_31/file_55.txt" "Dir_Num_31/file_58.txt" "Dir_Num_31/file_59.txt"
[37] "Dir_Num_31/file_61.txt" "Dir_Num_31/file_68.txt" "Dir_Num_31/file_70.txt" "Dir_Num_31/file_75.txt"
[41] "Dir_Num_41/file_77.txt" "Dir_Num_41/file_78.txt" "Dir_Num_41/file_80.txt" "Dir_Num_41/file_81.txt"
[45] "Dir_Num_41/file_82.txt" "Dir_Num_41/file_83.txt" "Dir_Num_41/file_88.txt" "Dir_Num_41/file_89.txt"
[49] "Dir_Num_41/file_93.txt" "Dir_Num_41/file_94.txt" "Dir_Num_51/file_96.txt" "Dir_Num_51/file_98.txt"

Answer 2

试试这个：

# generate random num
set.seed(15)
input <- rnorm(100, mean = 10, sd = 3)

# Write to file only if num is greater than threshold
thrshld <- 10
out_dir <- "~/R/tmp/Batch_Saving"

for (i in 1:length(input)) {

  # Create sub-folder if it doesn't exist
  sub_dir = paste0(out_dir, "/Dir_Num_", ceiling(i/10))
  dir.create(sub_dir, showWarnings = F)

  if ( input[i] > thrshld) {

    txt <- paste("The number", signif(input[i], 4), "is greater than", thrshld)

    # Write text to file
    writeLines(text = txt,
               con = paste0(sub_dir, "/file_", i, ".txt") )

  }

}

子文件夹中的文件数

sapply(list.dirs(), function(x)length(list.files(x)))

#            .  ./Dir_Num_1 ./Dir_Num_10  ./Dir_Num_2  ./Dir_Num_3  ./Dir_Num_4 
#           11            6            4            4            7            6 
#  ./Dir_Num_5  ./Dir_Num_6  ./Dir_Num_7  ./Dir_Num_8  ./Dir_Num_9 
#            7            6            3            4            5 

Answer 3

按照 nurandi 的回答，我添加了另一个计数器 c，它计算文件写入的次数，并使用 if-statement 检查它的数字增加了 10，每次它都创建一个新文件夹编号为k。

# generate random num
set.seed(15)
input <- rnorm(100, mean = 10, sd = 3)
# Write to file only if num is greater than threshold
thrshld <- 10
out_dir <- "~/R/tmp/Batch_Saving"
k <- 1
i <- 1
c <- 1
for (i in 1:length(input)) {

  if (input[i] > thrshld) {

    txt <- paste("The number", signif(input[i], 4), "is greater than", thrshld)

    if ( c %in% seq(from = 1, to = length(input), by = 10) ) {
      # Create a new subfolder everytime c is higher than a multiple of 10
      sub_dir <- paste0(out_dir, "/Dir_Num_", k) 
      k <- k + 1
    } 

    # Create folder if it doesn't exist
    if (!dir.exists(sub_dir)) { dir.create(sub_dir, recursive = T) }
    # Write text to file
    writeLines(text = txt,
               con = paste0(sub_dir, "/file_", i, ".txt") )

    # Increase wrote files counter to +1
    c <- c + 1
  }
}

使文件夹按递增顺序编号。

sapply(list.dirs(recursive = F), function(x) length( list.files(x) ) )

./Dir_Num_1 ./Dir_Num_2 ./Dir_Num_3 ./Dir_Num_4 
         10          10          10          10 
./Dir_Num_5 ./Dir_Num_6 
         10           2