我在XML中有很多行,我试图获得一个特定节点属性的实例。
<foo>
<bar>
<type foobar="1"/>
<type foobar="2"/>
</bar>
</foo>
我如何访问属性foobar的值?在这个例子中,我想要“1”和“2”。
我在XML中有很多行,我试图获得一个特定节点属性的实例。
<foo>
<bar>
<type foobar="1"/>
<type foobar="2"/>
</bar>
</foo>
我如何访问属性foobar的值?在这个例子中,我想要“1”和“2”。
当前回答
simplified_scrapy:一个新的库,我使用后就爱上了它。我向你推荐。
from simplified_scrapy import SimplifiedDoc
xml = '''
<foo>
<bar>
<type foobar="1"/>
<type foobar="2"/>
</bar>
</foo>
'''
doc = SimplifiedDoc(xml)
types = doc.selects('bar>type')
print (len(types)) # 2
print (types.foobar) # ['1', '2']
print (doc.selects('bar>type>foobar()')) # ['1', '2']
这里有更多的例子。这个库很容易使用。
其他回答
lxml。物化真的很简单。
以示例文本为例:
from lxml import objectify
from collections import defaultdict
count = defaultdict(int)
root = objectify.fromstring(text)
for item in root.bar.type:
count[item.attrib.get("foobar")] += 1
print dict(count)
输出:
{'1': 1, '2': 1}
我推荐ElementTree。同样的API还有其他兼容的实现,比如lxml和Python标准库中的cElementTree;但是,在这种情况下,他们主要增加的是更快的速度——编程的容易程度取决于ElementTree定义的API。
首先从XML中构建一个Element实例根,例如使用XML函数,或者通过解析文件,例如:
import xml.etree.ElementTree as ET
root = ET.parse('thefile.xml').getroot()
或者在ElementTree中显示的许多其他方法中的任何一种。然后这样做:
for type_tag in root.findall('bar/type'):
value = type_tag.get('foobar')
print(value)
输出:
1
2
如果源文件是一个xml文件,就像这个示例一样
<pa:Process xmlns:pa="http://sssss">
<pa:firsttag>SAMPLE</pa:firsttag>
</pa:Process>
您可以尝试下面的代码
from lxml import etree, objectify
metadata = 'C:\\Users\\PROCS.xml' # this is sample xml file the contents are shown above
parser = etree.XMLParser(remove_blank_text=True) # this line removes the name space from the xml in this sample the name space is --> http://sssss
tree = etree.parse(metadata, parser) # this line parses the xml file which is PROCS.xml
root = tree.getroot() # we get the root of xml which is process and iterate using a for loop
for elem in root.getiterator():
if not hasattr(elem.tag, 'find'): continue # (1)
i = elem.tag.find('}')
if i >= 0:
elem.tag = elem.tag[i+1:]
dict={} # a python dictionary is declared
for elem in tree.iter(): #iterating through the xml tree using a for loop
if elem.tag =="firsttag": # if the tag name matches the name that is equated then the text in the tag is stored into the dictionary
dict["FIRST_TAG"]=str(elem.text)
print(dict)
输出将是
{'FIRST_TAG': 'SAMPLE'}
#If the xml is in the form of a string as shown below then
from lxml import etree, objectify
'''sample xml as a string with a name space {http://xmlns.abc.com}'''
message =b'<?xml version="1.0" encoding="UTF-8"?>\r\n<pa:Process xmlns:pa="http://xmlns.abc.com">\r\n\t<pa:firsttag>SAMPLE</pa:firsttag></pa:Process>\r\n' # this is a sample xml which is a string
print('************message coversion and parsing starts*************')
message=message.decode('utf-8')
message=message.replace('<?xml version="1.0" encoding="UTF-8"?>\r\n','') #replace is used to remove unwanted strings from the 'message'
message=message.replace('pa:Process>\r\n','pa:Process>')
print (message)
print ('******Parsing starts*************')
parser = etree.XMLParser(remove_blank_text=True) #the name space is removed here
root = etree.fromstring(message, parser) #parsing of xml happens here
print ('******Parsing completed************')
dict={}
for child in root: # parsed xml is iterated using a for loop and values are stored in a dictionary
print(child.tag,child.text)
print('****Derving from xml tree*****')
if child.tag =="{http://xmlns.abc.com}firsttag":
dict["FIRST_TAG"]=child.text
print(dict)
### output
'''************message coversion and parsing starts*************
<pa:Process xmlns:pa="http://xmlns.abc.com">
<pa:firsttag>SAMPLE</pa:firsttag></pa:Process>
******Parsing starts*************
******Parsing completed************
{http://xmlns.abc.com}firsttag SAMPLE
****Derving from xml tree*****
{'FIRST_TAG': 'SAMPLE'}'''
simplified_scrapy:一个新的库,我使用后就爱上了它。我向你推荐。
from simplified_scrapy import SimplifiedDoc
xml = '''
<foo>
<bar>
<type foobar="1"/>
<type foobar="2"/>
</bar>
</foo>
'''
doc = SimplifiedDoc(xml)
types = doc.selects('bar>type')
print (len(types)) # 2
print (types.foobar) # ['1', '2']
print (doc.selects('bar>type>foobar()')) # ['1', '2']
这里有更多的例子。这个库很容易使用。