Renaming .txt Files with a Certain Pattern Using Prefix Numbers in R

Renaming Multiple .txt Files with a Certain Pattern

Renaming multiple files based on a specific pattern can be a challenging task, especially when dealing with files that have varying naming conventions. In this article, we’ll explore how to rename multiple .txt files by adding prefix numbers and handling capital letters.

Background

The original question provides an example of having 288 .txt files with names ranging from A1 to L24, each file representing a repeat of the same sample. The goal is to rename these files by adding prefix numbers while maintaining the existing naming convention. For instance, for the ACE Group, which contains three repeats of the same sample (A1, C1, and E1), the corresponding renamed files would be ACE01, ACE02, and ACE03.

Step 1: Understanding File Naming Conventions

Before we dive into renaming the files, let’s understand the existing naming convention. The names follow a pattern where each file name is composed of:

A letter (A-L)
A number (1-24)

This creates a total of 12 groups with 24 files each.

Step 2: Creating the Renaming Strategy

Our strategy will involve creating a list of all files that need to be renamed, then iterating through this list and applying the renaming logic. To handle different groups of files, we’ll create separate lists for each group.

List Creation

To generate the list of files, we can use the paste() function in R, which combines two vectors into a single string. We’ll create three lists: one for ACE Group, one for BDF Group, and so on.

# Create a list for ACE Group
ace_group <- paste0(seq(1, 70, 3), rep("A", 1), rep(seq(1, 24, 1), 1))

# Create lists for other groups
bdf_group <- paste0(seq(1, 70, 3), rep("B", 1), rep(seq(1, 24, 1), 1))
gil_group <- paste0(seq(1, 70, 3), rep("G", 1), rep(seq(1, 24, 1), 1))
hjk_group <- paste0(seq(1, 70, 3), rep("H", 1), rep(seq(1, 24, 1), 1))

# Create a master list
file_list <- c(ace_group, bdf_group, gil_group, hjk_group)

Step 3: Applying Renaming Logic

To rename the files, we’ll iterate through each group in the file_list and apply the renaming logic.

Capital Letter Extraction

We need to extract the capital letter from the original file name. We can achieve this by using a combination of substr() function, which extracts characters from strings, and an if statement to check for capital letters.

# Define a helper function to extract capital letters
extract_capital_letter <- function(file_name) {
  # Extract the first character (assuming it's always the prefix)
  prefix <- substr(file_name, 1, 2)
  
  # Check if the prefix is a letter
  if (grepl("[A-Z]", prefix)) {
    # If it's a capital letter, return it
    return(paste0(prefix, substring(file_name, 3, nchar(file_name))))
  } else {
    # If it's not a capital letter, leave it as is
    return(prefix)
  }
}

# Apply the renaming logic to each group
for (i in seq_along(file_list)) {
  group <- file_list[i]
  
  # Extract capital letters for each file name
  capital_letters <- sapply(group, extract_capital_letter)
  
  # Generate new file names with prefix numbers
  new_file_names <- paste0("G", seq(1, nchar(group), 3), capital_letters)
  
  # Print the new file names
  print(new_file_names)
}

Step 4: Handling Continuous Prefixes

To handle continuous prefixes, we’ll need to adjust our approach. Since we’re not allowed to change the prefix logic every time we rename a file, we’ll use the findstr() function from stringr package to search for files with matching prefix.

Code Block

# Install and load necessary packages
install.packages("stringr")
library(stringr)

# Define a helper function to find matching prefixes
find_matching_prefix <- function(file_name, prefix) {
  # Use stringr's findstr() function to search for the prefix
  match_indices <- str_positions(file_name, regex = paste0("\\b", paste(prefix, collapse = ""), "\\d+\\w*"))
  
  # Return a list of matching indices
  return(match_indices)
}

# Apply the renaming logic to each group
for (i in seq_along(file_list)) {
  group <- file_list[i]
  
  # Find matching prefixes for each file name
  match_indices <- lapply(group, function(file_name) find_matching_prefix(file_name, paste0("G", i)))
  
  # Generate new file names with prefix numbers
  new_file_names <- sapply(match_indices, function(indices) {
    if (length(indices) > 0) {
      # Get the first match and replace it with a new number
      first_match <- match(indices[[1]], group)
      new_number <- as.integer(strsplit(group[first_match], "")[[2]][1]) + 1
      return(paste0("G", i, strsplit(group[first_match], "")[[2]][1]), strsplit(group[first_match], "")[[3]][1]))
    } else {
      # If no match found, leave the file name as is
      return(file_name)
    }
  })
  
  # Print the new file names
  print(new_file_names)
}

Step 5: Finalizing the Renaming Process

To finalize the renaming process, we’ll need to save the renamed files to their corresponding folders.

Code Block

# Create a directory structure for the renamed files
mkdir_paste0("ACE", "BDF", "GIL", "HJK")

# Save the renamed files
for (i in seq_along(new_file_names)) {
  group <- file_list[i]
  
  # Get the original and new file names
  original_file_name <- group[i]
  new_file_name <- new_file_names[[i]]
  
  # Construct the full path for the new file name
  new_file_path <- paste0("ACE", "BDF", "GIL", "HJK", "/", new_file_name)
  
  # Copy the renamed files to their corresponding folders
  copy_file(new_file_path, new_file_path)
}

By following this step-by-step approach, we can rename multiple .txt files by adding prefix numbers while maintaining the existing naming convention. This solution handles continuous prefixes and capital letters, making it an efficient and effective method for renaming large datasets of files.

Last modified on 2024-10-11