Delete lines from a string that contains a keyword

[JellyCreeper6]

I want to delete lines from a string that contains a certain keyword.
How do I do this?

You can't do that. Strings are immutable so you cant delete lines. This does not mean that you can't achieve desired result but it will not be 'deleting lines from string'. It will be either printing selected parts from string or creating new string. In code above s have not changed and no lines are deleted from string.

Well, creating a new string is what I meant then, my bad