finished iterators chapter

examples/fibonacci2.py

@@ -1,11 +1,14 @@
 """Fibonacci iterator"""
 
 class Fib:
+    """iterator that yields numbers in the Fibanocci sequence"""
+
     def __init__(self, max):
         self.max = max
 
     def __iter__(self):
-        self.a, self.b = 0, 1
+        self.a = 0
+        self.b = 1
         return self
 
     def __next__(self):