<td class="text" align="center" style="font-family: Arial, sans-serif; color:#646464; font-size: 13px; line-height: 15px; text-decoration: line-through;">
<span style="font-family: Arial, sans-serif; color:#646464; font-size: 13px; line-height: 15px; text-decoration: line-through;">
53.63 Р<!-- <span class="oldprice4">53,63</span> -->
</span>
</td>53.63 Р в Beautiful Soup 4? 
>>> stroka = """<td class="text" align="center" style="font-family: Arial, sans-serif; color:#646464; font-size: 13px; line-height: 15px; text-decoration: line-through;">
... <span style="font-family: Arial, sans-serif; color:#646464; font-size: 13px; line-height: 15px; text-decoration: line-through;">
... 53.63 Р<!-- <span class="oldprice4">53,63</span> -->
... </span>
... </td>"""
>>> from lxml import etree
>>> from io import StringIO
>>> parser = etree.HTMLParser()
>>> tree = etree.parse(StringIO(stroka), parser)
>>> tree.xpath('.//td/span')[0].text
'\n 53.63 Р'>>> tree.xpath('.//td/span')[0].text.replace('\n','').strip()
'53.63 Р'
bs_stroka = bs4.BeautifulSoup(stroka)
bs_stroka.find('td').get_text().strip()