Python equivalent of continuations with Ruby

Question

What is the Python equivalent of the following code in Ruby?

def loop
  cont=nil
  for i in 1..4
    puts i
    callcc {|continuation| cont=continuation} if i==2
  end
  return cont
end

> c=loop
1
2
3
4
> c.call
3
4

Reference: Secrets of lightweight development success, Part 9: Continuations-based frameworks