I woud like to remove (delete) specific rows in csv file. But there are some conditions.
1.) File can't be buffered in memmory, becuse of it's size (1GB+)
2.) File MUST NOT be "touched" (rewriting file)
My job is just to delete some rows in csv file, without changing any other rows - Very important, becuse of encoding and sending filtered csv file to company which prints that files.
Is there solution?
Thank you!
It can't be done. You want to delete content from a file, without modifying it. Those are mutually exclusive.
You can try using the mmap interface to replace the row bytes by space characters.
You can create an old timestamp using 'touch -t'. See the man page of 'touch' for more details.
touch -t 200510071138 old.dat
Just make sure you write down the original timestamp!
In order to remove the rows, you can use 'grep -v', which prints everything except your search terms.
grep -v baddata old.dat > new.dat
To modify with python, we're going to need some specific details of the file.