此特定 xml 的 xml 解析答案

【问题标题】：xml parsing for this specific xml此特定 xml 的 xml 解析
【发布时间】：2015-10-19 14:19:40
【问题描述】：

    <instance id="activate.v.bnc.00024693" docsrc="BNC">
<answer instance="activate.v.bnc.00024693" senseid="38201"/>
<context>
Do you know what it is ,  and where I can get one ?  We suspect you had seen the Terrex Autospade ,  which is made by Wolf Tools .  It is quite a hefty spade , with bicycle - type handlebars and a sprung lever at the rear , which you step on to <head>activate</head> it . Used correctly ,  you should n't have to bend your back during general digging ,  although it wo n't lift out the soil and put in a barrow if you need to move it !  If gardening tends to give you backache ,  remember to take plenty of rest periods during the day ,  and never try to lift more than you can easily cope with .  
</context>
</instance>

我想提取里面的所有文本。这是我目前拥有的。 stuff.text 只打印<head></head> 之前的文本（即你知道吗...踩到），但我不知道如何提取</head> 之后的后半部分（即它。使用...容易...应付。）

import xml.etree.ElementTree as et
tree = et.parse(os.getcwd()+"/../data/train.xml")
instance = tree.getroot()

    for stuff in instance:
        if(stuff.tag == "answer"):
            print "the correct answer is %s" % stuff.get('senseid')
        if(stuff.tag == "context"):
            print dir(stuff)
            print stuff.text

【问题讨论】：

标签： python xml

【解决方案1】：

如果使用 BeautifulSoup 是一种选择，那将是微不足道的：

import bs4
xtxt = '''        <instance id="activate.v.bnc.00024693" docsrc="BNC">
    <answer instance="activate.v.bnc.00024693" senseid="38201"/>
    <context>
    Do you know what it is ,  and where I can get one ?  We suspect you had seen the Terrex Autospade ,  which is made by Wolf Tools .  It is quite a hefty spade , with bicycle - type handlebars and a sprung lever at the rear , which you step on to <head>activate</head> it . Used correctly ,  you should n't have to bend your back during general digging ,  although it wo n't lift out the soil and put in a barrow if you need to move it !  If gardening tends to give you backache ,  remember to take plenty of rest periods during the day ,  and never try to lift more than you can easily cope with .  
    </context>
    </instance>'''
soup = bs4.BeautifulSoup(xtxt)
print soup.find('context').text

给予：

Do you know what it is ,  and where I can get one ?  We suspect you had
seen the Terrex Autospade ,  which is made by Wolf Tools .  It is quite 
a hefty spade , with bicycle - type handlebars and a sprung lever at the 
rear , which you step on to activate it . Used correctly ,  you shouldn't 
have to bend your back during general digging ,  although it wo n't lift 
out the soil and put in a barrow if you need to move it !  If gardening 
tends to give you backache ,  remember to take plenty of rest periods 
during the day ,  and never try to lift more than you can easily cope 
with .

如果你更喜欢使用 ElementTree，你应该使用itertext 来处理所有的文本：

import xml.etree.ElementTree as et
tree = et.parse(os.getcwd()+"/../data/train.xml")
instance = tree.getroot()

    for stuff in instance:
        if(stuff.tag == "answer"):
            print "the correct answer is %s" % stuff.get('senseid')
        if(stuff.tag == "context"):
            print dir(stuff)
            print ''.join(stuff.itertext())

如果你确定你的 xml 文件是正确的，ElementTree 就足够了，因为它是标准 Python 库的一部分，你将没有外部依赖。但如果 XML 格式不正确，BeautifulSoup 非常适合修复小错误。

【讨论】：

【解决方案2】：

可以使用元素序列化。有两种选择：

保留内部<head></head>
只返回不带任何标签的文本。

如果使用标签进行序列化，可以手动删除外部<context></context>标签：

# convert element to string and remove <context></context> tag
print(et.tostring(stuff).strip().lstrip('<context>').rstrip('</context>')))
# read only text without any tags
print(et.tostring(stuff, method='text'))

【讨论】：