reformat in vim for a nice column layout

If you're on some kind of UNIX (Linux, etc), you can cheat and filter it through the column(1) command.

:%!column -t

The above will parse on delimiters inside string literals which is wrong, so you will likely need pre-processing steps and specifying the delimiter for this file for example:

%!sed 's/","/\&/' | column -t -s '&'

As sunny256 suggested, the column command is a great way of doing this on Unix/Linux machines, but if you want to do it in pure Vim (so that it can be used in Windows as well), the easiest way is to install the Align plugin and then do:

:%Align ,
:%s/\(\s\+\),\s/,\1/g

The first line aligns the entries on the commas and the second moves the comma so that it's flush with the preceding value. You may be able to use AlignCtrl to define a custom mapping that does the whole lot in one go, but I can never remember how to use it...

Edit

If you don't mind two spaces between entries and you want to do this in one command, you can also do:

:%Align ,\zs

Here’s a pure Vim script answer, no plugins, no macros:

It might be most clear to start out with my problem’s solution as an example. I selected the lines of code I wanted to affect, then used the following command (recall that entering command mode from visual mode automatically prepends the “'<,'>”, so it acts on the visual range):

:'<,'>g``normal / "value<0d>D70|P`

Except I did NOT actually type “<0d>”. You can enter unprintable characters on the command line by pressing ctrl-v, then the key you want to type. “<0d>” is what is rendered on the command line after I typed ‘ctrl-v enter’. Here, it’s parsed by the “normal” command as the exit from “/” search mode. The cursor then jumps to “ value” in the current line.

Then we simply [D]elete the rest of the line, jump to column 70 (or whatever you need in your case), and [P]ut what we just deleted. This does mean we have to determine the width of the widest line, up to our search. If you haven’t put that information in your statusline, you can see the column of the cursor by entering the normal mode command ‘g ctrl-g’. Also note that jumping to a column that doesn’t exist requires the setting 'virtualedit'!

I left the search term for the :g(lobal) command empty, since we used a visual block and wanted to affect every line, but you can leave off using a visual selection (and the “'<,'>”) and put a search term there instead. Or combine a visual selection and a search term to narrow things more finely/easily.

Here’s something I learned recently: if you mess up on a complex command mode command, undo with ‘u’ (if it affected the buffer), then press “q:” to enter a special command history buffer that acts much like a conventional buffer. Edit any line and press enter, and the changed command is entered as a new command. Indispensable if you don’t want to have to stress over formulating everything perfectly the first time.

I have this in my .vimrc.

command! CSV set nowrap | %s/,/,|/g | %!column -n -t -s "|" 

This aligns the columns while keeping the comma, which may be needed later for correct reading. For example, with Python Pandas read_csv(..., skipinitialspace=True), thanks Pandas guys for this smart option, otherwise in vim %s/,\s\+/,/g. It may be easier if your column has the option --output-separator I guess, my doesn't and I'm not sure why (my man page for column says 2004, on ubuntu 18.04, not sure ubuntu will get a new version). Anyway, this works for me, and comment if you have any suggestions.