python - "Expected string or buffer"使用 Beautiful Soup 时出错

Question

我正在尝试使用 Beautiful Soup 从 URL 中提取数字，然后对这些数字求和的代码，但我不断收到如下所示的错误:

Expected string or buffer

我认为这与正则表达式有关，但我无法确定问题所在。

import re
import urllib

from BeautifulSoup import *
htm1 = urllib.urlopen('https://pr4e.dr-chuck.com/tsugi/mod/python-data/data/comments_42.html').read()
soup = BeautifulSoup(htm1)
tags = soup('span')

for tag in tags:
    y = re.findall ('([0-9]+)',tag.txt)

print sum(y)

Answer 1

我推荐 bs4 而不是 BeautifulSoup(旧版本)。您还需要更改此行:

y = re.findall ('([0-9]+)',tag)

像这样:

y = re.findall ('([0-9]+)',tag.text)

看看这是否能让你更进一步:

sum = 0  #initialize the sum
for tag in tags:
    y = re.findall ('([0-9]+)',tag.text)  #get the text from the tag                                                                                                                                    
    print(y[0])  #y is a list, print the first element of the list                                                                                                                                      
    sum += int(y[0])  #convert it to an integer and add it to the sum                                                                                                                                   

print('the sum is: {}'.format(sum))