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export - Splitting a text file into smaller text files by line numbers using Mathematica


Is it possible to split a large text file into smaller files by line numbers in Mathematica?



Answer



Yes, of course.


text = Import["http://www.norvig.com/big.txt"];

StringLength[text]

(* 6488665 *)

lines = StringSplit[text, "\n"];
Length[lines]

(* 128457 *)

breaks = Union[Append[Range[1, Length[lines], 20000], Length[lines]]];


MapIndexed[
 Export["~/Downloads/textPart" <> ToString[#2[[1]]] <> ".txt", 
  Take[lines, #1], "Text"] &, Partition[breaks, 2, 1]]

(* {"~/Downloads/textPart1.txt", "~/Downloads/textPart2.txt", \
"~/Downloads/textPart3.txt", "~/Downloads/textPart4.txt", \
"~/Downloads/textPart5.txt", "~/Downloads/textPart6.txt", \
"~/Downloads/textPart7.txt"}*)


Verification with Unix / Mac OS commands:


[14:40:26]Downloads> ls | grep textPart | xargs -Iaaa wc aaa
   20000  239243 1398793 textPart1.txt
   20000  166040 1042501 textPart2.txt
   20000  155655  948331 textPart3.txt
   20000  166764  948771 textPart4.txt
   20000  169422  964634 textPart5.txt
   20000  167882  957716 textPart6.txt
    8456   30737  228187 textPart7.txt

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