Need help with autocmd in vim 7.0 - Editors

I have this line in my ~/.vimrc:

au BufNewFile *.py | execute "normal i# vim: set ts=4 sw=4 filetype=python:\<CR>\<CR>__date__ = \"$Date: $\"\<CR>__author__ = \"$Author: $\"\<CR>__revision__ = \"$Revision: $\"\<ESC>"

The point is so that every time I make a new python script, I start the
file with a template.

When I upgraded to vim 7, this config started generating errors. For
example, when I tried to edit a new file, x.py, I got this error
message:

"x.py" [New File]
Error detected while processing BufNewFile Auto commands for "*.py":
E749: empty buffer
Press ENTER or type command to continue

What am I doing wrong?

More generally, is there a more appropriate way that I can define
templates for new files, based on the file name suffix?

TIA

Matt


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