1 class C: 2 def __init__(self): 3 self.a = 1 4 self.c = 3 5 6 b = 2 7 8 class D: 9 def __init__(self): 10 self.a = 3 11 self.b = 4 12 13 class E: 14 a = 5 15 b = 6 16 17 def f(x): 18 return x.a, x.b 19 20 def g(x): 21 22 # Should only permit D instance and E. 23 24 x.a = 7 25 x.b = 8 26 return f(x) 27 28 def h(x): 29 x.c 30 x.a = 4 31 x.b 32 return f(x) 33 34 c = C() 35 d = D() 36 e = E() 37 38 print f(c) # (1, 2) 39 print f(d) # (3, 4) 40 print f(e) # (5, 6) 41 print f(E) # (5, 6) 42 43 try: 44 print g(c) # should fail with an error caused by a test 45 except TypeError: 46 print "g(c): c is not a suitable argument." 47 48 print g(d) # (7, 8) 49 50 try: 51 print g(e) # should fail with an error caused by a test 52 except TypeError: 53 print "g(e): e is not a suitable argument." 54 55 print g(E) # (7, 8) 56 57 print h(c) # (4, 2)
