# How to make a better Sort in my case

I have some file names like this:

fileNames = {"F:\\mathematica\\liu3\\62.jpg",
"F:\\mathematica\\liu3\\1.jpg", "F:\\mathematica\\liu3\\2.jpg",
"F:\\mathematica\\liu3\\3.jpg", "F:\\mathematica\\liu3\\4.jpg",
"F:\\mathematica\\liu3\\5.jpg", "F:\\mathematica\\liu3\\6.jpg",
"F:\\mathematica\\liu3\\7.jpg", "F:\\mathematica\\liu3\\42.jpg",
"F:\\mathematica\\liu3\\52.jpg"};


I want get a better order for they.But when I use Sort for this

Sort@fileNames


Then I get:

{"F:\mathematica\liu3\1.jpg", "F:\mathematica\liu3\2.jpg", \ "F:\mathematica\liu3\3.jpg", "F:\mathematica\liu3\42.jpg", \ "F:\mathematica\liu3\4.jpg", "F:\mathematica\liu3\52.jpg", \ "F:\mathematica\liu3\5.jpg", "F:\mathematica\liu3\62.jpg", \ "F:\mathematica\liu3\6.jpg", "F:\mathematica\liu3\7.jpg"}

But actually this ordering is my expectation

So how to get this list with my ordering by a terse method?

• You are getting the same sort order as your OS give you, i.e., lexical order. The easiest way to fix this is not in Mathematica, but in your file system. Rename flies such as 3.jpg to 03.jpg or to 30.jpg, whichever way seem more useful to you. Mar 25, 2016 at 5:40
• Thanks for you advices.1)I have try some order in my Window 10,but have no my expected order,and I have not found that order you mean like lexical order.2)The original name is 3.jpg,4.jpg or 42.jpg.to add that 0 is little troublesome.3)I wanna sort it in mma because of I wannt import it into mma then convenient to following processing
– yode
Mar 25, 2016 at 5:52
• Your screenshot looks quite strange, where's Name(名称)? And I can't find fonts related options in my OS, I'm using Win10, too. Mar 25, 2016 at 5:59
• @xzczd Click the More(更多).
– yode
Mar 25, 2016 at 6:09
• You should check 排序方式, not 分组依据 囧 Mar 25, 2016 at 8:11

SortBy[#, FileBaseName] &@fileNames

• brilliant work ! +1 Mar 25, 2016 at 10:47
• I just noticed @xzczd's comment, which I agree with, that your file naming convention is not clear. For instance, does "123" mean the 23rd in the 1st group, or 3rd in 12th group? Better solution would be figured out were more clear naming convention provided. Mar 25, 2016 at 11:24
• Yep,I'm aware of that confict.So I have already deleted it.Thank for your help. :)
– yode
Mar 25, 2016 at 11:28
• Interesting, I didn't know "." doesn't take part in sorting. Mar 25, 2016 at 11:42

#[[Ordering[StringTake[FileBaseName@# <> "0", 2] & /@ #]]] &@fileNames

• As you promption of FileBaseName,then I get another try like fileNames[[Ordering[StringPadRight[FileBaseName/@fileNames,Automatic,"0"]]]],Thank you very much.
– yode
Mar 25, 2016 at 6:07
• @yode Oh, so there're functions for string padding in v10. (I'm still in v9. ) Mar 25, 2016 at 8:21
• I don' t know whether or not appropriate I update this post.
– yode
Mar 25, 2016 at 8:46
• @yode Then since the serial number isn't limited to 0~9, your naming rule turns out to be unclear. For example, should "42" be taken as "42, 1st" or "4, 2nd"? Mar 25, 2016 at 9:05
• Seems to be little unclear,But in my casy "42" mean "4, 2nd"
– yode
Mar 25, 2016 at 9:19

there is a nasty way of doing this:

orig = (Riffle[ToCharacterCode[fileNames], (Characters /@ fileNames)]) //
Partition[#, 2] & // Thread[#] & /@ # & // #[[All, {21, 22}]] &

(*{{{54, "6"}, {50, "2"}}, {{49, "1"}, {46, "."}}, {{50, "2"}, {46,"."}},
{{51, "3"}, {46, "."}}, {{52, "4"}, {46, "."}}, {{53,"5"}, {46, "."}},
{{54, "6"}, {46, "."}}, {{55, "7"}, {46,"."}}, {{52, "4"}, {50, "2"}},
{{53, "5"}, {50, "2"}}} *)

sorted = Flatten[Position[orig, #] &/@ Sort@orig]

(* {2, 3, 4, 5, 9, 6, 10, 7, 1, 8} *)

fileNames[[sorted]]

(* {"F:\\mathematica\\liu3\\1.jpg", "F:\\mathematica\\liu3\\2.jpg",
"F:\\mathematica\\liu3\\3.jpg", "F:\\mathematica\\liu3\\4.jpg",
"F:\\mathematica\\liu3\\42.jpg", "F:\\mathematica\\liu3\\5.jpg",
"F:\\mathematica\\liu3\\52.jpg", "F:\\mathematica\\liu3\\6.jpg",
"F:\\mathematica\\liu3\\62.jpg", "F:\\mathematica\\liu3\\7.jpg"} *)

• you are welcome ! Mar 25, 2016 at 11:37