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1960 :: Natural Sorting

• qwertyuiop (orginal) [2016-01-21T06:34:36+01:00] view original

  Hi. Say I have this:

  
  import future
  import os
  var x = lc[ file | (file <- walkFiles("*")), string]
  echo x
  Run

  Simple program, gets a list of files in a directory and stores them in "x."

  If I have {1..11}.jpg in a directory, x would be @[1.jpg, 10.jpg, 11.jpg, 2.jpg, 3.jpg, 4.jpg, 5.jpg, 6.jpg, 7.jpg, 8.jpg, 9.jpg].

  How would I go about sorting this in natural order, as humans expect it to be: @[1.jpg, 2.jpg, 3.jpg, 4.jpg, 5.jpg, 6.jpg, 7.jpg, 8.jpg, 9.jpg, 10.jpg, 11.jpg]?

  I looked at http://nedbatchelder.com/blog/200712.html#e20071211T054956, which works for Python, but not for Nim, because the functions can return two different types, int or str.

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• Urban (orginal) [2016-01-21T10:16:36+01:00] view original

  You could define a function which takes two file names and converts them to -1,0 or 1. I would do something like this:

  
  import future
  from algorithm import sort
  from os import extract_file_name, walk_files, split_file
  from strutils import parse_int, is_digit
  
  proc file_name_cmp(f1, f2: string): int =
    let f_name1 = f1.split_file[1]
    let f_name2 = f2.split_file[1]
    if f_name1.is_digit and f_name2.is_digit:
      return system.cmp[int](f_name1.parse_int, f_name2.parse_int)
    else:
      return system.cmp(f_name1, f_name2)
  
  var x = lc[ file | (file <- walk_files("*")), string]
  x.sort(file_name_cmp)
  Run

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• qwertyuiop (orginal) [2016-01-22T01:24:08+01:00] view original

  Many thanks. I greatly appreciate it.

  I made two small changes, though. I changed line 4 to

  from strutils import parse_int, is_digit, toLower
  Run

  and line 12 to

  return system.cmp(f_name1.toLower, f_name2.toLower)
  Run

  This causes

  
  @[1.jpg, 2.jpg, 3.jpg, 4.jpg, 5.jpg, 6.jpg, 7.jpg, 8.jpg, 9.jpg, 10.jpg, 11.jpg, A1.jpg, C.jpg, F1.png, a0, b.bpg, d.gif]
  Run

  to instead be sorted as

  
  @[1.jpg, 2.jpg, 3.jpg, 4.jpg, 5.jpg, 6.jpg, 7.jpg, 8.jpg, 9.jpg, 10.jpg, 11.jpg, a0, A1.jpg, b.bpg, C.jpg, d.gif, F1.png]
  Run

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• Urban (orginal) [2016-01-22T22:57:28+01:00] view original

  No problem! :)

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