easing switching between Git and Mercurial

For a long time I've been meaning to write a script that eases switching between the only VCS systems I use, Mercurial and Git. Each chance I get, I use Mercurial (e.g. personal stuff), and use Git when I don't have much of a choice (e.g. FLOSS and work). That is, I use both quite a lot, and too often I find myself running commands for one while on another's repository.

I then decided to ease the pain my creating a script which checks which VCS system I'm on, and displays the relevant command. Here are the relevant aliases:

alias vb='$(python ~/projects/utils/vcs.py --branch)'
alias vd='$(python ~/projects/utils/vcs.py --diff)'
alias vl='$(python ~/projects/utils/vcs.py --log)'
alias vp='$(python ~/projects/utils/vcs.py --push)'
alias vs='$(python ~/projects/utils/vcs.py --status)'
alias vu='$(python ~/projects/utils/vcs.py --pull)'
alias vc='$(python ~/projects/utils/vcs.py --commit)'
alias vo='$(python ~/projects/utils/vcs.py --checkout)'
alias vr='$(python ~/projects/utils/vcs.py --revert)'

Displaying the output instead of running them directly from the script gives me the flexibility of adding to the command, for example:

# committing
vc 'describe the change'
# checking history of a file

This makes my life so much easier, since I no longer have to care where I'm at, at least for the most common of commands. I am pleased with self.