How can I run a different command but with the same arguments?

Use !*. It expands to all words except the first one (i.e. the command).

$ vim arbit.py
$ python !*
python arbit.py

You can combine it with all the features of !, for example:

$ vim arbit.py
$ ls
$ python !vim:*
vim arbit.py

Or, if you want only the last word, there are two other ways:

$ vim arbit.py
$ python !$

or:

$ vim arbit.py
$ python <Esc+.>

See the bash history interaction documentation for more details.

There are at least a couple of ways to do this.

$ vim arbit.py
$ python[press Alt-.]

which retrieves the last argument of the previous command as does:

$ vim arbit.py
$ python !$

or

$ vim arbit.py
$ python !*

which retrieves all the arguments of the previous command.