import re
str = '<tr class="img weatherIcoS"> <td class="p1"> title="это не атрибут, а просто текст" <!-- title="а эта штука вообще внутри комментария"  --> <div class="weatherIco n000" title="Ясно"><img alt="" class="weatherImg" src="//sinst.fwdcdn.com/img/weatherImg/s/n000.gif"/></div> </td> <td class="p2 bR"> <div class="weatherIco n000" title="Ясно"><img alt="" class="weatherImg" src="//sinst.fwdcdn.com/img/weatherImg/s/n000.gif"/></div> </td> <td class="p3"> <div class="weatherIco d300" title="Облачно с прояснениями"><img alt="" class="weatherImg" src="//sinst.fwdcdn.com/img/weatherImg/s/d300.gif"/></div> </td> <td class="p4 bR"> <div class="weatherIco d300" title="Облачно с прояснениями"><img alt="" class="weatherImg" src="//sinst.fwdcdn.com/img/weatherImg/s/d300.gif"/></div> </td> <td class="p5 cur"> <div class="weatherIco d300" title="Облачно с прояснениями"><img alt="" class="weatherImg" src="//sinst.fwdcdn.com/img/weatherImg/s/d300.gif"/></div> </td> <td class="p6 bR"> <div class="weatherIco d320" title="Облачно с прояснениями, дождь"><img alt="" class="weatherImg" src="//sinst.fwdcdn.com/img/weatherImg/s/d320.gif"/></div> </td> <td class="p7"> <div class="weatherIco d320" title="Облачно с прояснениями, дождь"><img alt="" class="weatherImg" src="//sinst.fwdcdn.com/img/weatherImg/s/d320.gif"/></div> </td> <td class="p8"> <div class="weatherIco n300" title="Облачно с прояснениями"><img alt="" class="weatherImg" src="//sinst.fwdcdn.com/img/weatherImg/s/n300.gif"/></div> </td> </tr>'
titles = re.findall(r'title="([^"]*)"', str)
print(titles)

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