ch06

ch06/iterators/iterator.py

@@ -0,0 +1,53 @@
+# iterators/iterator.py
+class OddEven:
+
+    def __init__(self, data):
+        self._data = data
+        self.indexes = (list(range(0, len(data), 2)) +
+            list(range(1, len(data), 2)))
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.indexes:
+            return self._data[self.indexes.pop(0)]
+        raise StopIteration
+
+oddeven = OddEven('ThIsIsCoOl!')
+print(''.join(c for c in oddeven))  # TIICO!hssol
+
+oddeven = OddEven('CiAo')  # or manually...
+it = iter(oddeven)  # this calls oddeven.__iter__ internally
+print(next(it))  # C
+print(next(it))  # A
+print(next(it))  # i
+print(next(it))  # o
+
+
+# make sure it works correctly with edge cases
+oddeven = OddEven('')
+print(' '.join(c for c in oddeven))
+
+oddeven = OddEven('A')
+print(' '.join(c for c in oddeven))
+
+oddeven = OddEven('Ab')
+print(' '.join(c for c in oddeven))
+
+oddeven = OddEven('AbC')
+print(' '.join(c for c in oddeven))
+
+
+"""
+$ python iterators/iterator.py
+TIICO!hssol
+C
+A
+i
+o
+
+A
+A b
+A C b
+"""