How to Read the Files in a Directory in Sorted Order Using R

How can I read the files in a directory in sorted order using R?

Why not retrieve all files (with a particular pattern) with list.files() and then sort that. Then you retrieve the files from the sorted vector, which gives them to you in correctly sorted order. This has the advantage that it also works when numbers are missing from the 1:365 sequence

Something like:

myFiles <- list.files(pattern = "^Climate_Rad_") #all files starting with Climate_
myFiles <- sort(myFiles)
# then read them in, for instance through
for (fileNames in myFiles) {READ.IN.AND.DO.YOUR.MAGIC.ON.THEM}

sorting files and read according to basename in R

Just use order to get an ordered vector of indices to rearrange the original vector of files:

files <- c("path/b01.csv","path/a01.csv", "path/a02.csv")
files[order(basename(files))]

[1] "path/a01.csv" "path/a02.csv" "path/b01.csv"

list files in ascending order

As far as computers are concerned, it is sorting correctly. However, you can used mixedsort from the "gtools" package to get the type of sorting you want:

> myFiles <- paste("file", 1:20, ".txt", sep = "")
> sort(myFiles)
 [1] "file10.txt" "file11.txt" "file12.txt" "file13.txt" "file14.txt" "file15.txt"
 [7] "file16.txt" "file17.txt" "file18.txt" "file19.txt" "file1.txt"  "file20.txt"
[13] "file2.txt"  "file3.txt"  "file4.txt"  "file5.txt"  "file6.txt"  "file7.txt" 
[19] "file8.txt"  "file9.txt" 
> library(gtools)
> mixedsort(sort(myFiles))
 [1] "file1.txt"  "file2.txt"  "file3.txt"  "file4.txt"  "file5.txt"  "file6.txt" 
 [7] "file7.txt"  "file8.txt"  "file9.txt"  "file10.txt" "file11.txt" "file12.txt"
[13] "file13.txt" "file14.txt" "file15.txt" "file16.txt" "file17.txt" "file18.txt"
[19] "file19.txt" "file20.txt"

With your example, that means you can do:

files <- list.files(pattern = ".txt")
library(gtools)
files <- mixedsort(files)

User functions are fun

Since it's easy to write little utility functions, you can also write a little function like this:

ListFiles <- function(pattern = ".txt") {
  require(gtools)
  myFiles <- list.files(pattern = pattern, )
  mixedsort(myFiles)
}

Then, compare:

list.files(pattern = ".txt")
ListFiles(pattern = ".txt")

Reading and listing objects in the order they appear in the source file in R

There's no way to get the order of variable definition after sourcing the file without explicitly recording the order in the file itself. One way to do this would be to put the variables in a list.

How to sort files list by date?

You can use the file.info function to obtain details on your files. Once you have those details, you can sort the files accordingly. For example,

details = file.info(list.files(pattern="*.csv"))

gives a data frame containing, inter alia, modification and creation times. You can sort that data frame however you want. Here I sort according to modification time, mtime:

details = details[with(details, order(as.POSIXct(mtime))), ]
files = rownames(details)

Reading files in directory in sorted order Python

Try sorting the files list using sorted.

Ex:

root_dir = r'C:\Users\ab\pythonfiles\Compressed_images'
for root, dirs, files in os.walk(root_dir):
    for file in sorted(files, key=lambda x: int(x.split(".")[0])):
        print('For file: \n', file)

Sorting files in the directory including case sensitivity in C

#include <stdio.h>
#include <dirent.h>
#include <string.h>
int main(void)
{
    char array[50][30]={};
    int i=0, j=0, k=0;
    DIR *d;
    struct dirent *dir;
    d = opendir(".");
    printf("d: %d \n",d);    
    if (d)
    {
        while ((dir = readdir(d)) != NULL)
        {
            strcpy(array[i], dir->d_name);
            i++;
        }
        for (k = 0; k <= i; k++)    /* Sorting files alphabetically */
            for (j = k + 1; j <= i; j++)
            {
                if (strcasecmp(array[k], array[j]) > 0)
                {
                    strcpy(tmp, array[k]);
                    strcpy(array[k], array[j]);
                    strcpy(array[j], tmp);
                }
            }
        closedir(d);
      }
      for (int a = 0 ; a < i ; a++)
      {
          printf("%s \n",array[a]);
      }
      return 0;
}