1 a = 123 2 3 def f(x): 4 global a 5 a = x 6 7 def g(a): 8 b = a 9 10 def h(b): 11 a = b 12 13 class A: 14 x = a 15 global a 16 y = a 17 18 f(234) 19 g(345) 20 h(456)