python - Need for Performance in bash script -
i have 50000 files , each 1 has 10000 lines. each line in form:
value_1 (tab) value_2 (tab) ... value_n
i wanted remove specific values every line in every file (i used cut remove values 14-17) , write results new file.
for doing in 1 file, wrote code:
file=nameoffile newfile=$file".new" i=0 while read line let i=i+1 echo line: $i a=$i"p" linefirstpart=$(sed -n -e $a $file | cut -f 1-13) #echo linefirstpart: $linefirstpart linesecondpart=$(sed -n -e $a $file | cut -f 18-) #echo linesecondpart: $linesecondpart newline=$linefirstpart$linesecondpart echo $newline >> $newfile done < $file
this takes ~45 secs 1 file, means take about: 45x50000 = 625h ~= 26 days!
well, i need faster, e.g. solution cats whole file, applies 2 cut commands simultaneusly or guess.
also solutions in python accepted + appreciated bash scripting preferable!
the entire while
loop can replaced 1 line:
cut -f1-13,18- $file > $newfile
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