python解析xml库lxml-XPath-马育民老师

需要掌握：
[XPath](https://www.malaoshi.top/show_1EF504RvgguN.html "XPath")
[python解析xml库lxml](https://www.malaoshi.top/show_1EF504JL0LdB.html "python解析xml库lxml")

### xml内容
```
<?xml version='1.0' encoding='utf-8'?>

<articles>
    <abstract>该文档是测试数据</abstract>
    <article title="解析xml" time="2020-03-15 12:00" like_num="593" discuss_num="327" author="张三">
        <abstract>文章摘要</abstract>
        <content>文章正文</content>
    </article>

<article title="python入门到放弃" time="2019-01-15 12:00" like_num="6493" discuss_num="33427" author="灭霸">
        <abstract>python入门到放弃摘要</abstract>
        <content>python入门到放弃正文</content>
    </article>

</articles>
```

# 查找节点

### 获取所有x节点，不论任何位置
获取所有`abstract`节点，不论任何位置：
```
from lxml import etree

tree=etree.parse("/Users/mym/Desktop/python/2.xml")
article=tree.xpath("//abstract")
print(article,len(article))

for item in article:
    print(item.tag,item.text)
```
执行结果：
```
abstract 该文档是测试数据
abstract 文章摘要
abstract python入门到放弃摘要
```

### 获取指定位置的所有x节点
获取 `/articles/article/`路径下的`abstract`节点：
```
from lxml import etree

tree=etree.parse("/Users/mym/Desktop/python/2.xml")
article=tree.xpath("/articles/article/abstract")
print(article,len(article))

for item in article:
    print(item.tag,item.text)
```
执行结果：
```
abstract 文章摘要
abstract python入门到放弃摘要
```

### 获取所有节点
（很少这么用）
```
from lxml import etree

tree=etree.parse("/Users/mym/Desktop/python/2.xml")
article=tree.xpath("//*")
print(article,len(article))

for item in article:
    print(item.tag,item.text)
```

### 根据属性值获取节点

获取author是灭霸的节点：

```
from lxml import etree

tree=etree.parse("/Users/mym/Desktop/python/2.xml")
article=tree.xpath("/articles/article[@author='灭霸']")
print(article,len(article))

for item in article:
    print(item.tag,item.get("title"))
```

# 属性

### 获取指定属性的值
获取`/articles/article`标签的`title`属性值
```
tree=etree.parse("/Users/mym/Desktop/python/2.xml")
article=tree.xpath("/articles/article/@title")
print(article,len(article))

for item in article:
    print(item)
```
执行结果：
```
['解析xml', 'python入门到放弃'] 2
解析xml
python入门到放弃
```

# 标签文本

### 获取指定标签的文本内容
获取所有`abstract`标签的文本
```
from lxml import etree

tree=etree.parse("/Users/mym/Desktop/python/2.xml")
article=tree.xpath("//abstract/text()")
print(article,len(article))

for item in article:
    print(item)
```
执行结果：
```
['该文档是测试数据', '文章摘要', 'python入门到放弃摘要'] 3
该文档是测试数据
文章摘要
python入门到放弃摘要
```

感谢：
https://www.cnblogs.com/zhangxinqi/p/9210211.html

原文出处：http://malaoshi.top/show_1EF505k06HSS.html