如何在R中通过‘arg’匹配并加载以其开头的.RData文件？

Hey there! I totally get why you tried load("arg*.RData") first—wouldn't that be convenient if it worked straight away? Unfortunately, R's load() function doesn't support wildcard patterns like * natively. But we can fix this with a simple two-step approach using base R functions.

Step 1: Find All Matching Files #

First, we need to locate every .RData file that starts with arg, even those nested in subfolders. Use list.files() with a regular expression pattern to target these files:

# Get full paths of all arg-prefixed .RData files (including subfolders)
target_files <- list.files(
  pattern = "^arg.*\\.RData$",  # Regex to match files starting with "arg" and ending with ".RData"
  recursive = TRUE,             # Look through all subfolders
  full.names = TRUE             # Return full file paths instead of just filenames
)

Let's break down the regex pattern:

• ^arg: Ensures the filename starts exactly with "arg"
• .*: Matches any sequence of characters (of any length) between "arg" and the file extension
• \\.RData$: Ensures the file ends with .RData (the backslash escapes the dot, which is a special character in regex)

If you don't need to search subfolders, just set recursive = FALSE. You can also specify a specific root folder with the path parameter if needed:

target_files <- list.files(
  path = "/path/to/your/main/folder",
  pattern = "^arg.*\\.RData$",
  recursive = TRUE,
  full.names = TRUE
)

Step 2: Load the Files #

Once we have our list of files, we can loop through them and load each one. A for loop is straightforward and lets you add progress messages if you want:

# Load each file into the global environment
for (file in target_files) {
  cat("Loading", basename(file), "...\n")  # Optional: Print progress
  load(file)
}

Alternatively, you can use lapply() for a more concise approach:

# Load all files with lapply
lapply(target_files, load, envir = .GlobalEnv)

Bonus: Load Objects into a List (Instead of Global Env) #

If you prefer to keep all loaded objects organized in a single list (instead of cluttering your global environment), use this variation:

# Load each file's contents into a named list
loaded_data <- lapply(setNames(target_files, basename(target_files)), function(file) {
  temp_env <- new.env()
  load(file, envir = temp_env)
  as.list(temp_env)
})

# Access objects like this: loaded_data[["arg_233_1_1.RData"]]

That's it! This method will reliably load all your arg-prefixed .RData files without having to specify each one individually.

内容的提问来源于stack exchange，提问作者user321627