need help translating a PHP for statement to python

[Davis Marques]

hi;

I'm translating some PHP scripts to Python and have hit a roadblock
with a for statement.  If someone could explain to me how one should
translate the multiple increment, evaluations, etc. in the first line
I would appreciate it deeply ...

for ($y = 0, $x = $cx-$cy-1; $y <= $cy; ++$y,++$x) {
    $prd = $q * $y_ar[$y] + $car;
    $prd -= ($car = intval($prd / 1E7)) * 1E7;
    if ($bar = (($x_ar[$x] -= $prd + $bar) < 0)) $x_ar[$x] += 1E7;
    }

thanks,


Davis