如何在Python中使用break跳出多层循环？

<span class="k">for</span> <span class="n">a</span> <span class="ow">in</span> <span class="nb">xrange</span><span class="p">(</span><span class="mi">10</span><span class="p">):</span>
    <span class="k">for</span> <span class="n">b</span> <span class="ow">in</span> <span class="nb">xrange</span><span class="p">(</span><span class="mi">20</span><span class="p">):</span>
        <span class="k">if</span> <span class="n">something</span><span class="p">(</span><span class="n">a</span><span class="p">,</span> <span class="n">b</span><span class="p">):</span>
            <span class="c"># Break the inner loop...</span>
            <span class="k">break</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="c"># Continue if the inner loop wasn't broken.</span>
        <span class="k">continue</span>
    <span class="c"># Inner loop was broken, break the outer.</span>
    <span class="k">break</span>