Vim: insert the same characters across multiple lines

Question

Sometimes I want to edit a certain visual block of text across multiple lines.

For example, I would take a text that looks like this:

name
comment
phone
email

And make it look like this

vendor_name
vendor_comment
vendor_phone
vendor_email

Currently the way I would do it now is...

1. Select all 4 row lines of a block by pressing V and then j four times.
2. Indent with >.
3. Go back one letter with h.
4. Go to block visual mode with Ctrlv.
5. Select down four rows by pressing j four times. At this point you have selected a 4x1 visual blocks of whitespace (four rows and one column).
6. Press C. Notice this pretty much indented to the left by one column.
7. Type out a " vendor_" without the quote. Notice the extra space we had to put back.
8. Press Esc. This is one of the very few times I use Esc to get out of insert mode. Ctrlc would only edit the first line.
9. Repeat step 1.
10. Indent the other way with <.

I don't need to indent if there is at least one column of whitespace before the words. I wouldn't need the whitespace if I didn't have to clear the visual block with c.

But if I have to clear, then is there a way to do what I performed above without creating the needed whitespace with indentation?

Also why does editing multiple lines at once only work by exiting out of insert mode with Esc over Ctrlc?

---

Here is a more complicated example:

name    = models.CharField( max_length = 135 )
comment = models.TextField( blank = True )
phone   = models.CharField( max_length = 135, blank = True )
email   = models.EmailField( blank = True )

to

name    = models.whatever.CharField( max_length = 135 )
comment = models.whatever.TextField( blank = True )
phone   = models.whatever.CharField( max_length = 135, blank = True )
email   = models.whatever.EmailField( blank = True )

In this example I would perform the vertical visual block over the ., and then reinsert it back during insert mode, i.e., type .whatever.. Hopefully now you can see the drawback to this method. I am limited to only selecting a column of text that are all the same in a vertical position.

Answer 1

1. Move the cursor to the n in name.
2. Enter visual block mode (Ctrlv).
3. Press j three times (or 3j).
4. Press I (capital i).
5. Type in vendor_. Note: It will only update the screen in the first line - until Esc is pressed (6.), at which point all lines will be updated.
6. Press Esc.

An uppercase I must be used rather than a lowercase i, because the lowercase i is interpreted as the start of a text object, which is rather useful on its own, e.g. for selecting inside a tag block (it):