2012-11-15 90 views
3

我已经得到了我使用Xapi检索快餐店一些OSM数据,并here是一些示例结果:BeautifulSoup发现XML标签

<osm version="0.6" generator="Osmosis SNAPSHOT-r26564"> 
    <node id="486275964" version="4" timestamp="2010-05-03T08:21:42Z" uid="12055" user="aude" changeset="4592597" lat="38.8959533" lon="-77.0212458"> 
     <tag k="name" v="Potato Valley Cafe"/> 
     <tag k="amenity" v="fast_food"/> 
    </node> 
    <node id="486275966" version="4" timestamp="2010-08-06T16:44:13Z" uid="207745" user="NE2" changeset="5418228" lat="38.8959399" lon="-77.0196338"> 
     <tag k="cuisine" v="burger"/> 
     <tag k="name" v="McDonald's"/> 
     <tag k="amenity" v="fast_food"/> 
    </node> 
    <node id="612190923" version="1" timestamp="2010-01-12T14:01:27Z" uid="111209" user="cov" changeset="3603297" lat="38.893683" lon="-77.0292732"> 
     <tag k="level" v="-1"/> 
     <tag k="cuisine" v="sandwich"/> 
     <tag k="name" v="Quizno's"/> 
     <tag k="amenity" v="fast_food"/> 
    </node> 
</osm> 
<!--corrected indentation--> 

我试图用BeautifulSoup在Python中提取拉特,长,名称和美食。我可以用这个代码得到lat和长没有问题:

soup = BeautifulSoup(results) 
takeaways = soup.findAll('node') 

for eachtakeaway in takeaways: 
    longitude = str(eachtakeaway['lon']) 
    lattitude = str(eachtakeaway['lat']) 

但我不能得到名称:

name = str(eachtakeaway['name']) 

其中抛出了错误:

TypeError: 'NoneType' object is not callable 

灿你告诉我该怎么办?谢谢。

回答

4

的问题是,在方括号检索标签,即latlon的属性。但是,名称是另一个标签的属性。尝试这样的:

soup = BeautifulSoup(results) 
takeaways = soup.findAll('node') 

for eachtakeaway in takeaways: 
    another_tag = eachtakeaway('tag') 
    for tag_attrs in another_tag: 
     if str(tag_attrs['k']) == 'cuisine': 
      print str(tag_attrs['v']) 

这将返回美食价值。同样的概念适用于检索name

*未经测试

+0

bs4有一个xml模式。围绕为什么要使用XML模式,在这样一个实例任何想法? – kalu

+1

@kalu我BS4的经验是有限的,但我在BS4 XML模式支持XML命名空间,区分大小写标签处理等XML的细节的印象是。我不能保证这一点,因为我只从朋友/同事交谈图纸,也没有研究此事。 – That1Guy

2

<node>元素没有name属性。标签的子标签的作用:

for eachtakeaway in takeaways: 
    longitude = str(eachtakeaway['lon']) 
    lattitude = str(eachtakeaway['lat']) 
    nametag = eachtakeaway.find('tag', k='name') 
    name = str(nametag['v']) if nametag is not None else '' 

示范:

>>> takeaways = soup.findAll('node') 
>>> for eachtakeaway in takeaways: 
...  nametag = eachtakeaway.find('tag', k='name') 
...  print str(nametag['v']) if nametag is not None else '' 
... 
Potato Valley Cafe 
McDonald's 
Quizno's