Mel/Python: Adding number padding

I was looking through some older scripts and hit across my dirty attempt to add number padding, and I was surprised it actually worked.
I went about tidying it up and came up with this little number in mel.
global proc string rt_addPadding(int $num,int $padding) { int $lengthNum=size(string($num)) ; string $padString; if($lengthNum<$padding) for($i=0;$i<($padding-$lengthNum);$i++) $padString=$padString+"0" ; return $padString+string($num) ; }
Which works ok, and then a couple of minutes searching I came across a post by Nathan which instead uses python (and is far better).
string $pad = `python ("'%0"+$padding+"d' % "+$num)`;
This then is used as this.global proc string rt_addPadding(int $num,int $padding) { return `python("'%0"+$padding+"d' % "+$num)` ; }
Useful :)