How to generate sequence number and append to line before pattern match in a file

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How to get expected output for an input file like below and output should be as below using any program awk/sed/perl/shell/python. please help

input:

abc
APPLE
123
456
789
def
APPLE
321
654
987
.
.
.

expected Output: append sequence before pattern (APPLE is pattern here) match

abc1
APPLE
123
456
789
def2
APPLE
321
654
987
.
.

What I have tried:

Nothing as of now, please help

Posted 17-Mar-21 2:20am

Santosh Kumar 2021

Updated 17-Mar-21 2:48am

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Comments

OriginalGriff 17-Mar-21 8:45am

This is not a good question - we cannot work out from that little what you are trying to do.
Remember that we can't see your screen, access your HDD, or read your mind - we only get exactly what you type to work with. And especially when your input and expected output examples are identical ...
Use the "Improve question" widget to edit your question and provide better information.

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CPallini · Accepted Answer · 2021-03-17T02:48:00

Solution 1

Try

Python

fin = open('input.txt', 'r')
fout = open('output.txt', 'w')

linesin = fin.read().splitlines()

seqnum = 1
previous = None
for lin in linesin:
  if previous != None:
    if lin == 'APPLE':
      previous += str(seqnum)
      seqnum = seqnum + 1
    fout.write(previous+'\n')
  previous = lin

fout.write(previous+'\n')
fout.close()
fin.close()

Posted 17-Mar-21 2:48am

CPallini

Comments

Santosh Kumar 2021 17-Mar-21 10:00am

Thanks a lot CPallini. above solution solved my problem

CPallini 17-Mar-21 10:23am

You are welcome.