How to delete a line by its line number?
To delete a specific line of a file by its line number: Replace variables filename and line_to_delete with the name of your file and the line number you want to delete. Take the contents of the file, split it by newline into a tuple. Then, access your tuple’s line number, join your result tuple, and overwrite to the file.
How to delete nth lines in a Unix file?
If you want to delete Nth line only if it contains a pattern, then in place of $ place the line number. Note: In all the above examples, the sed command prints the contents of the file on the unix or linux terminal by removing the lines. However the sed command does not remove the lines from the source file.
How to delete specific lines in a file in memory?
In the end, remove the original file and rename the temporary file as the original file.” It will give the impression that we have deleted the specific lines from the file. This file can be a simple text file or a CSV file. With this approach, we can remove lines from huge files too, in a memory-efficient way.
Is there a way to remove lines from a source file?
However the sed command does not remove the lines from the source file. To Remove the lines from the source file itself, use the -i option with sed command. If you dont wish to delete the lines from the original source file you can redirect the output of the sed command to another file.
How to delete a line from a file in Python?
First, open the file and get all your lines from the file. Then reopen the file in write mode and write your lines back, except for the line you want to delete: You need to strip (” “) the newline character in the comparison because if your file doesn’t end with a newline character the very last line won’t either.
Can a sed script save a file of line numbers?
Humorously (but perhaps slightly confusingly) you can do this with sed. This accepts a file of line numbers, one per line, and produces, on standard output, the same line numbers with d appended after each. This is a valid sed script, which we can save to a file, or (on some platforms) pipe to another sed instance: