pack/unpack a generator
<p>I have a two generators. First generator sometimes needs to call second generator and yield back values it got from there:</p>

<pre><code>def a():
    for _b in b():
        yield _b

def b():
    yield 1
    yield 2

for _a in a():
    print _a
</code></pre>

<p>Is there a more elegant way to do this:</p>

<pre><code>for _b in b():
    yield _b
</code></pre>

<p>I've tried this:</p>

<pre><code>yield *b()
</code></pre>

<p>But surely it doesn't work. I have Python 2.6.</p>
