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R Sort strings according to a substring

I have a set of file names, such as:

filelist <- c("filea-10.txt", "fileb-2.txt", "filec-1.txt", "filed-5.txt", "filef-4.txt")

and I would like to filter them according to the number after the "-".

In python, for example, I can use the keysort function parameter :

filelist <- ["filea-10.txt", "fileb-2.txt", "filec-1.txt", "filed-5.txt", "filef-4.txt"]
sorted(filelist, key=lambda(x): int(x.split("-")[1].split(".")[0]))

> ["filec-1.txt", "fileb-2.txt", "filef-4.txt", "filed-5.txt", "filea-10.txt"]

In R, I play with strsplitand lapplywithout luck.

What is the way to do this in R?

Edit : File names may be different, and may contain more numbers. The only fixed pattern is that the number I want to sort happens after the "-". Another (real) example:

c <- ("boards10017-51.mp4",  "boards10065-66.mp4",  "boards10071-81.mp4",
      "boards10185-91.mp4", "boards10212-63.mp4",  "boards1025-51.mp4",   
      "boards1026-71.mp4",   "boards10309-89.mp4", "boards10310-68.mp4",  
      "boards10384-50.mp4",  "boards10398-77.mp4",  "boards10419-119.mp4", 
      "boards10421-85.mp4",  "boards10444-87.mp4",  "boards10451-60.mp4",  
      "boards10461-81.mp4",  "boards10463-52.mp4",  "boards10538-83.mp4",  
      "boards10575-62.mp4",  "boards10577-249.mp4")"
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1 answer

I'm not sure the real complexity of your list of file names, but the following may be enough:

filelist[order(as.numeric(gsub("[^0-9]+", "", filelist)))]
# [1] "filec-1.txt"  "fileb-2.txt"  "filef-4.txt"  "filed-5.txt"  "filea-10.txt"

, gsub - :

gsub(".*-|\\..*", "", filelist)

, , , .

:

 x <- c("boards10017-51.mp4", "boards10065-66.mp4", "boards10071-81.mp4", 
     "boards10185-91.mp4", "boards10212-63.mp4", "boards1025-51.mp4",     
     "boards1026-71.mp4", "boards10309-89.mp4", "boards10310-68.mp4",     
     "boards10384-50.mp4", "boards10398-77.mp4", "boards10419-119.mp4",   
     "boards10421-85.mp4", "boards10444-87.mp4", "boards10451-60.mp4",    
     "boards10461-81.mp4", "boards10463-52.mp4", "boards10538-83.mp4",    
     "boards10575-62.mp4", "boards10577-249.mp4")  

x[order(as.numeric(gsub(".*-|\\..*", "", x)))]
##  [1] "boards10384-50.mp4"  "boards10017-51.mp4"  "boards1025-51.mp4"  
##  [4] "boards10463-52.mp4"  "boards10451-60.mp4"  "boards10575-62.mp4" 
##  [7] "boards10212-63.mp4"  "boards10065-66.mp4"  "boards10310-68.mp4" 
## [10] "boards1026-71.mp4"   "boards10398-77.mp4"  "boards10071-81.mp4" 
## [13] "boards10461-81.mp4"  "boards10538-83.mp4"  "boards10421-85.mp4" 
## [16] "boards10444-87.mp4"  "boards10309-89.mp4"  "boards10185-91.mp4" 
## [19] "boards10419-119.mp4" "boards10577-249.mp4"
+5

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