# -*- encoding:utf-8 -*-

'''
@Author : dingjiawen
@Date : 2023/11/8 15:15
@Usage : 
@Desc :
'''

from lxml import etree

'''
XPath基本规则:

    1)  nodename:选择此节点的所有子节点
    2)  /:从当前节点选取直接子节点
    3)  //:从当前阶段选择子孙节点
    4)  .:选取当前节点
    5)  ..:选取当前节点的父节点
    6)  @:选取属性

举例:
//title[@lang='eng]代表选择所有名称为title,同时属性lang的值为eng的节点
'''


def htmlByString():
    text = '''
    <div>
        <ul>
             <li class="item-0"><a href="link1.html">first item</a></li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-inactive"><a href="link3.html">third item</a></li>
             <li class="item-1"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a>
         </ul>
     </div>
    '''
    html = etree.HTML(text)
    result = etree.tostring(html)
    print(result.decode('utf-8'))


def htmlByFile():
    html = etree.parse('./test.html', etree.HTMLParser())
    result = etree.tostring(html)
    print(result.decode('utf-8'))


def allNode():
    html = etree.parse('./test.html', etree.HTMLParser())
    # 从头开始匹配所有的
    result = html.xpath('//*')
    print(result)
    print(result[0])

    # 匹配所有li的
    result = html.xpath('//li')
    print(result)
    print(result[0])


# 子节点匹配
def childNode():
    html = etree.parse('./test.html', etree.HTMLParser())

    # 匹配所有li的子节点a
    result = html.xpath('//li/a')
    print(result)
    print(result[0])

    # 匹配所有li的子孙节点a  相当于只要是子节点下面的就可以匹配上
    result = html.xpath('//ul//a')
    print(result)
    print(result[0])


# 父节点匹配
def fatherNode():
    html = etree.parse('./test.html', etree.HTMLParser())

    # 匹配a节点属性href是link4.html的父节点的class属性
    result = html.xpath('//a[@href="link4.html"]/../@class')
    print(result)
    # 也可以通过parent::来获取
    result = html.xpath('//a[@href="link4.html"]/parent::*/@class')
    print(result)


# 文本获取
def textGet():
    html = etree.parse('./test.html', etree.HTMLParser())

    # 匹配li节点属性class是item-0的节点的子节点a的text
    result = html.xpath('//li[@class="item-0"]/a/text()')
    print(result)  # ['first item', 'fifth item']

    # 匹配li节点属性class是item-0的节点的子孙节点的text
    result = html.xpath('//li[@class="item-0"]//text()')
    print(result)  # ['first item', 'fifth item', '\r\n    ']


# 属性获取
def fieldGet():
    html = etree.parse('./test.html', etree.HTMLParser())

    # 匹配li节点属性class是item-0的节点的子节点a的href属性
    result = html.xpath('//li/a/@href')
    print(result)  # ['link1.html', 'link2.html', 'link3.html', 'link4.html', 'link5.html']


# 属性多值匹配
def fieldsGet():
    text = '''
    <li class="li li-first"><a href="link.html">first item</a></li>
    '''
    html = etree.HTML(text)
    result = html.xpath('//li[@class="li"]/a/text()')
    print(result)  # [] 匹配不到

    result = html.xpath('//li[contains(@class, "li")]/a/text()')
    print(result)  # ['first item']  contains匹配到了


# 多属性匹配
def fieldssGet():
    text = '''
    <li class="li li-first" name="item"><a href="link.html">first item</a></li>
    '''
    html = etree.HTML(text)
    # 多属性用and连接
    result = html.xpath('//li[contains(@class, "li") and @name="item"]/a/text()')
    print(result)


# 按序选择
def orderGet():
    text = '''
    <div>
        <ul>
             <li class="item-0"><a href="link1.html">first item</a></li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-inactive"><a href="link3.html">third item</a></li>
             <li class="item-1"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a>
         </ul>
     </div>
    '''
    html = etree.HTML(text)
    result = html.xpath('//li[1]/a/text()')
    print(result)  # ['first item']
    result = html.xpath('//li[last()]/a/text()')
    print(result)  # ['fifth item']
    result = html.xpath('//li[position()<3]/a/text()')
    print(result)  # ['first item', 'second item']
    result = html.xpath('//li[last()-2]/a/text()')
    print(result)  # ['third item']


def nodeSelect():
    text = '''
    <div>
        <ul>
             <li class="item-0"><a href="link1.html"><span>first item</span></a></li>
             <li class="item-1"><a href="link2.html">second item</a></li>
             <li class="item-inactive"><a href="link3.html">third item</a></li>
             <li class="item-1"><a href="link4.html">fourth item</a></li>
             <li class="item-0"><a href="link5.html">fifth item</a>
         </ul>
     </div>
    '''
    html = etree.HTML(text)
    result = html.xpath('//li[1]/ancestor::*')
    print(result)
    # ancestor获取祖先
    result = html.xpath('//li[1]/ancestor::div')
    print(result)
    # attribute获取所有属性
    result = html.xpath('//li[1]/attribute::*')
    print(result)
    # child获取子节点
    result = html.xpath('//li[1]/child::a[@href="link1.html"]')
    print(result)
    # descendant获取子孙结点
    result = html.xpath('//li[1]/descendant::span')
    print(result)
    # following获取当前节点之后的所有节点
    result = html.xpath('//li[1]/following::*[2]')
    print(result)
    # following-sibling获取当前节点之后的同级节点
    result = html.xpath('//li[1]/following-sibling::*')
    print(result)

if __name__ == '__main__':
    nodeSelect()