<p>我不太明白我下面的代码有什么问题</p>
<pre><code>for stripe in [sku.value for sku in model_sheet.col(13) if str(sku.value)]:
try:
stripe = int(stripe)
except ValueError:
stripe = unicode(stripe)
for stars in [sku.value for sku in model_sheet.col(19) if str(sku.value)]:
yield HatInstance(hat_model, shade, cockade, rosette, color_ribbon, buttons, cover, stripe, stars, silk_band = silk_band)
</code></pre>
<p>它在第9行第5列显示IndentationError:unindent不匹配任何外部缩进级别。我没有正确地遵循正确的PEP8缩进吗?你知道吗</p>