How do you delete a first N line in Python?

How do you delete a first N line in Python?

To delete the first N lines use list slicing. If you are reading a file and don’t want to read the first line use the below approach instead of deleting a line from a file. To delete last N lines use list slicing.

How do you delete a line in a text file using Python?

Use del to delete a line from a file where its position is known {#use-del)

1. a_file = open(“sample.txt”, “r”) get list of lines.
2. lines = a_file. readlines()
3. a_file.
4. del lines[1] delete lines.
5. new_file = open(“sample.txt”, “w+”) write to file without line.
6. for line in lines:
7. new_file. write(line)
8. new_file.

How do you clear a line in Python?

How to clear screen in python?

1. From os import system.
2. Define a function.
3. Make a system call with ‘clear’ in Linux and ‘cls’ in Windows as an argument.
4. Store the returned value in an underscore or whatever variable you want (an underscore is used because python shell always stores its last output in an underscore).

How to remove first n lines of sql file?

This seems to be the easiest: Remove lines 1-42 from test.sql and save as test2.sql You can use Vim in Ex mode: Because of sed discrepancies across Linux and Mac, I resolved to use tail -n +43 dump.sql > new.sql format.

How to remove the last n lines of a file in Linux?

A straightforward sed one-liner sed ‘1,n d’ can remove the top n lines. After that, if we reverse the lines again, our problem gets solved. The tac command can reverse the order of lines in a file. That is, we can try to solve our problem through a command “tac INPUT_FILE | sed ‘1,n d’ | tac”.

How to delete the first 42 lines of a file?

The + sign is important – without it, tail will print the last 43 lines instead. Alternatively with ‘sed’ If you want to really delete the first 42 lines from the original file then you can make sed make the change inplace with the -i option

How to remove the last line from a variable?

Put this all together, and you can strip the last line out of your variable with: Since the count is going to be the full number of lines, $var.count – 1 would be the last line, so you want it to stop at the next to last line, or $var.count – 2.