[Tutor] multiline comment in Python

[Alan Gauld]

> i think the easiest way to do this with vi is using
> block-wise selection.  this will comment out the next 10
> lines:
> 
>   0[ctrl-v]10jI#

Note that is is not standard vi, its a vim feature.

In vi the way to do blocks is to provide the line numbers 
at the start of the command, the numbers can be relative 
or absolute:

.,+5<command>

applies command from the current line(.) to the next 5 lines(+5)

15,20<command> applies the command to lines 15 thru 20.

The latter is easiest if you have line numbering switched on.

But you can also use searches to define the block:

:+3,/foo/<command>

applies command to the block starting 3 lines down and extending 
to the next line containing 'foo'.

To create comment lines I usually use the substitute command:

:.,/foo/s/^/#/

This substitutes the start of a line(^) with a #

:.,/foo/s/^#//

removes it again.

Alan G.