Using vimrc function to pass python arguments

Question

I am attempting to create a vimrc function that will be used in an autocmd . The function must simply call a python script and pass the file name as an argument.

.vimrc

fu! Test(filename)
    let filename = expand("%:t")
    "echom filename
    !test.py filename

example.py

#!usr/bin/python
import sys

print sys.argv[1]

If I uncomment the echo line, example.py is echo'd correctly. If I try to execute as it is displayed above, however, the string filename is passed literally.

Is there any way around this?

Answer 1

Sure, you can use the execute command to execute a string, which is built from the command you want and the variable concatenated together:

fu! Test()
    let filename = expand("%:t")
    execute "!test.py " . l:filename
endfunction

I've omitted the filename argument in your Test function because it doesn't seem to be used

Answer 2

You have two options either you pass the filename directly as an argument or pass it as a local variable:

fu! Test(filename)
    "echom a:filename
    execute "!test.py ".a:filename

or

fu! Test()
    let l:filename = expand("%:t")
    "echom filename
    execute "!test.py ". l:filename