Beautiful Soup 如何提取类属性值？

Question

我用beautifulsoup提取class的多个属性值，但['fa', 'fa-address-book-o']不是我想要的结果。

from bs4 import BeautifulSoup

html = "<i class='fa fa-address-book-o' aria-hidden='true'></i>"

soup = BeautifulSoup(html, "lxml")

h2 = soup.select("i")

print(h2[0]['class'])

我希望效果如下：

fa fa-address-book-o