Question

我已经完成了一项任务，我必须从this xml file中提取数字然后总结它们。问题是，当我尝试执行for循环以获取数据时，我收到属性错误：

TypeError：＆＃39; NoneType＆＃39;对象不可调用

到目前为止，这是我的代码：

import urllib
import xml.etree.ElementTree as ET

url = raw_input('Enter location: ')
print 'Retrieving', url
uh = urllib.urlopen(url)
data = uh.read()
print 'Retrieved',len(data),'characters'
tree = ET.fromstring(data)
lst = tree.findall('.//count')
print 'Count:', len(lst)
for item in lst:
    print 'name', item.find('count').text

我应该从count标签中提取文本：

<comment>
  <name>Matthias</name>
  <count>97</count>
</comment>

我在这里找不到什么东西？

Answer 1

我建议使用Beautiful Soup。 http://www.crummy.com/software/BeautifulSoup/bs4/doc/

它使得解析xml文件非常容易

from bs4 import BeautifulSoup
soup = BeautifulSoup(data)  # It seems that your data variable holds the xml
for tag in soup.find_all('count'):
    print tag.get_text()

Answer 2

我尝试了我的代码并且成功了！

   import urllib
   import xml.etree.ElementTree as ET

   url = raw_input('Enter location: ')
   print 'Retrieving', url
   uh = urllib.urlopen(url)
   data = uh.read()
   print 'Retrieved',len(data),'characters'
   tree = ET.fromstring(data)
   lst = tree.findall('.//count')
   print 'Count:', len(lst)
   total = 0
   for comment in tree.findall("./comments/comment"):
       total += int(comment.find('count').text)
   print total

Answer 3

A.K。像Gabor Erdos说的那样。 BS4要好得多，但如果你想使用ElementTree：

import urllib
import xml.etree.ElementTree as ET
url = 'http://python-data.dr-chuck.net/comments_208135.xml'
tresc = urllib.urlopen(url).read()
tree = ET.fromstring(tresc)

wartosci = tree.findall('.//count')
sum = 0
count = 0

for item in wartosci:
    x = int(item.text)
    sum = sum + x
    count = count + 1

print('Retrieving', url)
print('Retrieving'), len(tresc), 'characters'
print('Count: ', count)
print('Sum: ', sum)

Answer 4

对于Python 3，这个无麻烦的代码应该适用于你的任务：

StackPanel

Answer 5

import urllib.request, urllib.parse, urllib.error
import xml.etree.ElementTree as ET

url = 'http://py4e-data.dr-chuck.net/comments_4772.xml'
print ('Retrieving', url)
uh = urllib.request.urlopen(url)
data = uh.read()
print('Retrieved', len(data), 'characters')
tree = ET.fromstring(data)
counts = tree.findall('.//count')
print ('Count',len(counts))
total=0
for item in counts:
    element=item.text
    total+=int(element)
print(total)

如何从这段数据中获取数字？

5 个答案: