Convert PHP code:
$this->plane[$slice_id][$f][] = array('x' => $y, 'y' => $z);
To python:
self.plane = {};
self.plane[slice_id][f][] = {'x' : y, 'y' : z};
Does not work.
1) self.plane[slice_id][f]
-> not yet initialized. Only create this element if necessary.
2) []
-> push element to array
3) Python dictionary are not usually multi-dimensional