class Foo:
   def __init__(self, x):
       self.x = x  # an n-d array

   def pop_q(q, tuple):
       q = zeros(tuple)

   def set_q(q, i, j=None, qq):
       if q.ndim == 1:
           q[i] = qq
       else if q.ndim == 2:
           q[i, :] = qq
       else if q.ndim == 3:
           q[i, j, :] = qq

   def get_q(q, i, j=None):
       if q.ndim == 1:
           return q[i]
       else if q.ndim == 2:
           return q[i, :]
       else if q.ndim == 3:
           return q[i, j, :]