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  <h3>Zip Generator</h3>
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<p>Write a generator that takes in any number of iterables and zips them together. It should output a series of lists, each containing the nth items of each iterable. It should stop when the smallest iterable runs out of elements. For example:</p>

<pre><code>def zip(     ):
    """
    &gt;&gt;&gt; z = zip([1, 2, 3], [4, 5, 6], [7, 8])
    &gt;&gt;&gt; for i in z:
    ...     print(i)
    ...
    [1, 4, 7]
    [2, 5, 8]
    """
    "***YOUR CODE HERE***"
</code></pre>

<p><a href="#solution" class="solution_toggle">Toggle Solution</a></p>

<div class="solution">

  <pre><code>def zip(*iterables):
    """
    &gt;&gt;&gt; z = zip([1, 2, 3], [4, 5, 6], [7, 8])
    &gt;&gt;&gt; for i in z:
    ...     print(i)
    ...
    [1, 4, 7]
    [2, 5, 8]
    """
    iterators = [iter(iterable) for iterable in iterables]
    while True:
        yield [next(iterator) for iterator in iterators]
</code></pre>

  <p>There were several concepts that were tested in this problem. The first was the * syntax most commonly associated with <code>*args</code>. Remember that <code>args</code> is just the name of the list of arguments, but the variable can be named anything. For this problem, we’re going to call it <code>iterables</code> because it’s going to be a list of iterables. Since they are iterables, we need to make them all into iterators so the best way to do this is call <code>iter</code> on each of the iterables to make iterators. This can also be done using <code>map</code>. Next, we need a loop that runs to the end of the shortest iterator, however, we note that when we reach the end of the shortest iterator, we need to raise a <code>StopIteration</code>. We then note that when calling <code>next</code> on an iterator that is out of elements, it raises a <code>StopIteration</code>! So, our job is mainly complete and we can just yield the next items of each iterator. When one iterator runs out of elements, it will raise a <code>StopIteration</code> which in turn will make the <code>zip</code> function return a <code>StopIteration</code> as well.</p>

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