Duck iterator

README.md

@@ -1046,6 +1046,24 @@ class MyCollection:
             yield el
 ```
 
+### Iterator
+```python
+class Counter:
+    def __init__(self):
+        self.i = 0
+    def __next__(self):
+        self.i += 1
+        return self.i
+    def __iter__(self):
+        return self
+```
+
+```python
+>>> counter = Counter()
+>>> next(counter), next(counter), next(counter)
+(1, 2, 3)
+```
+
 ### Callable
 ```python
 class Counter:

index.html

@@ -981,6 +981,20 @@ creature  = Creature(Point(<span class="hljs-number">0</span>, <span class="hljs
         <span class="hljs-keyword">for</span> el <span class="hljs-keyword">in</span> self.a:
             <span class="hljs-keyword">yield</span> el
 </code></pre>
+<h3 id="iterator-1">Iterator</h3>
+<pre><code class="python language-python hljs"><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Counter</span>:</span>
+    <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__init__</span><span class="hljs-params">(self)</span>:</span>
+        self.i = <span class="hljs-number">0</span>
+    <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__next__</span><span class="hljs-params">(self)</span>:</span>
+        self.i += <span class="hljs-number">1</span>
+        <span class="hljs-keyword">return</span> self.i
+    <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__iter__</span><span class="hljs-params">(self)</span>:</span>
+        <span class="hljs-keyword">return</span> self
+</code></pre>
+<pre><code class="python language-python hljs"><span class="hljs-meta">&gt;&gt;&gt; </span>counter = Counter()
+<span class="hljs-meta">&gt;&gt;&gt; </span>next(counter), next(counter), next(counter)
+(<span class="hljs-number">1</span>, <span class="hljs-number">2</span>, <span class="hljs-number">3</span>)
+</code></pre>
 <h3 id="callable">Callable</h3>
 <pre><code class="python language-python hljs"><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Counter</span>:</span>
     <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__init__</span><span class="hljs-params">(self)</span>:</span>