Indent or comment several text lines with vi

Question

can vim or vim be used to comment or indent at the same time a number of lines? For instance:

for item in Lista:
    ind = int(floor(1.0*(item-lmin)/width))
    if ind==nintervals:
        ind=ind-1
    print item,ind

comment it to:

#for item in Lista:
    #ind = int(floor(1.0*(item-lmin)/width))
    #if ind==nintervals:
        #ind=ind-1
    #print item,ind

or indent it to:

  for item in Lista:
      ind = int(floor(1.0*(item-lmin)/width))
      if ind==nintervals:
          ind=ind-1
      print item,ind

P.D. Is relevant the difference between VI and VIM?

Answer 1

here is another way.

1. block lines with ctrl+v
2. Insert comment sign (//) with I
3. escape with ESC

the key typing is

ctrl+v → jjjj → I → // → ESC

Answer 2

To comment, press a capital V to enter VISUAL LINE mode, select all lines, then press : to enter command mode and use the command (note that VIM already include the '<,'>marks for you):

:'<,'>s/^/#/

If you prefer hash marks near the text, and not near the left margin, the command is:

:'<,'>s/^\(\s*\)/\1#/

To indent, select the block the same, then type > to indent, < to unindent.