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Python基于lxml模塊解析html獲取頁面內(nèi)所有葉子節(jié)點(diǎn)xpath路徑功能示例

更新時間：2018年05月16日 12:19:34 作者：Together_CZ

這篇文章主要介紹了Python基于lxml模塊解析html獲取頁面內(nèi)所有葉子節(jié)點(diǎn)xpath路徑功能,結(jié)合實例形式較為詳細(xì)的分析了Python使用lxml模塊進(jìn)行xml節(jié)點(diǎn)數(shù)據(jù)解析的相關(guān)操作技巧與注意事項,需要的朋友可以參考下

本文實例講述了Python基于lxml模塊解析html獲取頁面內(nèi)所有葉子節(jié)點(diǎn)xpath路徑功能。分享給大家供大家參考，具體如下：

因為需要使用葉子節(jié)點(diǎn)的路徑來作為特征，但是原始的lxml模塊解析之后得到的卻是整個頁面中所有節(jié)點(diǎn)的xpath路徑，不是我們真正想要的形式，所以就要進(jìn)行相關(guān)的處理才行了，差了很多網(wǎng)上的博客和文檔也沒有找到一個是關(guān)于輸出html中全部葉子節(jié)點(diǎn)的API接口或者函數(shù)，也可能是自己沒有那份耐心，沒有找到合適的資源，只好放棄了尋找，但是這并不說明沒有其他的方法了，在對頁面全部節(jié)點(diǎn)的xpath輸出之后觀察得到的結(jié)果就是：

1.路徑之間存在包含性

2.葉子節(jié)點(diǎn)的路徑必然包含上一個葉子節(jié)點(diǎn)路徑到下一個葉子節(jié)點(diǎn)路徑之間的路徑

3.所有的葉子節(jié)點(diǎn)均不存在包含性

基于這些觀察就可以實踐了，我采用的方法是，設(shè)置一個標(biāo)志位，如果當(dāng)前路徑被下一條路徑包含的話就把下標(biāo)加1處理，直到遇上不包含的情況是這一條路徑就是一條葉子節(jié)點(diǎn)路徑，加入結(jié)果列表即可，經(jīng)檢驗和原始路徑列表對比后，結(jié)果路徑列表均不存在包含性，暫可認(rèn)為均為葉子節(jié)點(diǎn)的路徑，不敢確定的說是因為：竟沒有大量做實驗觀察是否有另類，不過方法是可行的，下面是具體實現(xiàn)：

#!usr/bin/env python
#encoding:utf-8
'''''
__author__:沂水寒城
功能：得到頁面的葉子節(jié)點(diǎn)的xpath
'''
def get_leaf_node_xpath(one_page_xpath):
  '''''
  輸入：一個頁面的原始xpath路徑列表
  輸出：只包含頁面的葉子節(jié)點(diǎn)的xpath列表
  '''
  one_page_xpath.append('0')
  leaf_node_xpath_list=[]
  for i in range(len(one_page_xpath)-1):
    j=i+1
    one_xpath=one_page_xpath[i]
    two_xpath=one_page_xpath[j]
    if one_xpath in two_xpath:
      one_xpath=two_xpath
      two_xpath=one_page_xpath[j+1]
    else:
      leaf_node_xpath_list.append(one_xpath)
  return leaf_node_xpath_list
if __name__ == '__main__':
  with open('baidu.txt') as f:
    html=f.read()
  htree, one_page_xpath=get_clean_allnodes_xpath(html)
  leaf_node_xpath_list=get_leaf_node_xpath(one_page_xpath)
  print leaf_node_xpath_list
  with open('data/dom_leaf_xpath/original_xpath.txt', 'w') as f1:
    for one_line in one_page_xpath:
      f1.write(one_line.strip()+'\n')
  with open('data/dom_leaf_xpath/leaf_xpath.txt', 'w') as f2:
    for one_line in leaf_node_xpath_list:
      f2.write(one_line.strip()+'\n')

打開保存的文件內(nèi)容為：

original_xpath.txt內(nèi)容為：

/html
/html/head
/html/head/meta[1]
/html/head/meta[2]
/html/head/meta[3]
/html/head/meta[4]
/html/head/title
/html/body
/html/body/p
/html/body/p/comment()[1]
/html/body/p/comment()[2]
/html/body/p/comment()[3]
/html/body/p/meta
/html/body/div[1]
/html/body/div[1]/div[1]
/html/body/div[1]/div[1]/div
/html/body/div[1]/div[1]/div/div[1]
/html/body/div[1]/div[1]/div/div[1]/div
/html/body/div[1]/div[1]/div/div[1]/div/div[1]
/html/body/div[1]/div[1]/div/div[1]/div/a
/html/body/div[1]/div[1]/div/div[1]/div/form
/html/body/div[1]/div[1]/div/div[1]/div/form/span[1]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[2]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/div
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/div/span
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[1]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[1]/a
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[2]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[2]/a
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[3]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[4]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[4]/a
/html/body/div[1]/div[1]/div/div[1]/div/div[2]
/html/body/div[1]/div[1]/div/div[2]
/html/body/div[1]/div[1]/div/div[2]/a[1]
/html/body/div[1]/div[1]/div/div[2]/a[2]
/html/body/div[1]/div[1]/div/div[2]/a[3]
/html/body/div[1]/div[1]/div/div[3]
/html/body/div[1]/div[1]/div/div[3]/a[1]
/html/body/div[1]/div[1]/div/div[3]/a[2]
/html/body/div[1]/div[1]/div/div[3]/a[3]
/html/body/div[1]/div[1]/div/div[3]/a[4]
/html/body/div[1]/div[1]/div/div[3]/a[5]
/html/body/div[1]/div[1]/div/div[3]/a[6]
/html/body/div[1]/div[1]/div/div[3]/a[7]
/html/body/div[1]/div[1]/div/div[3]/a[8]
/html/body/div[1]/div[1]/div/div[3]/a[9]
/html/body/div[1]/div[2]
/html/body/div[1]/div[2]/a[1]
/html/body/div[1]/div[2]/a[2]
/html/body/div[1]/div[2]/a[3]
/html/body/div[1]/div[2]/a[4]
/html/body/div[1]/div[2]/a[5]
/html/body/div[1]/div[2]/a[6]
/html/body/div[1]/div[2]/a[7]
/html/body/div[1]/div[2]/a[8]
/html/body/div[1]/div[2]/a[9]
/html/body/div[1]/div[3]
/html/body/div[1]/div[3]/div
/html/body/div[1]/div[3]/div/div
/html/body/div[1]/div[3]/div/div/div[1]
/html/body/div[1]/div[3]/div/div/div[2]
/html/body/div[1]/div[3]/div/div/div[2]/p
/html/body/div[1]/div[4]
/html/body/div[1]/div[4]/div
/html/body/div[1]/div[4]/div/div
/html/body/div[1]/div[4]/div/div/p[1]
/html/body/div[1]/div[4]/div/div/p[1]/a[1]
/html/body/div[1]/div[4]/div/div/p[1]/a[2]
/html/body/div[1]/div[4]/div/div/p[1]/a[3]
/html/body/div[1]/div[4]/div/div/p[1]/a[4]
/html/body/div[1]/div[4]/div/div/p[2]
/html/body/div[1]/div[4]/div/div/p[2]/a[1]
/html/body/div[1]/div[4]/div/div/p[2]/a[2]
/html/body/div[1]/div[4]/div/div/p[2]/a[3]
/html/body/div[1]/div[5]
/html/body/div[2]
/html/body/div[3]
/html/body/div[4]
0

最后一行的0只是為了代碼中列表能夠遍歷到最后一個路徑而不出現(xiàn)索引錯誤的一個簡單的處理，人為的添加了一個元素，沒有實際意義，也不會參與處理

leaf_xpath.txt內(nèi)容為：

/html/head/meta[1]
/html/head/meta[2]
/html/head/meta[3]
/html/head/meta[4]
/html/head/title
/html/body/p/comment()[1]
/html/body/p/comment()[2]
/html/body/p/comment()[3]
/html/body/p/meta
/html/body/div[1]/div[1]/div/div[1]/div/div[1]
/html/body/div[1]/div[1]/div/div[1]/div/a
/html/body/div[1]/div[1]/div/div[1]/div/form/span[1]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[2]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/div/span
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[1]/a
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[2]/a
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[3]
/html/body/div[1]/div[1]/div/div[1]/div/form/span[3]/span/ul/li[4]/a
/html/body/div[1]/div[1]/div/div[1]/div/div[2]
/html/body/div[1]/div[1]/div/div[2]/a[1]
/html/body/div[1]/div[1]/div/div[2]/a[2]
/html/body/div[1]/div[1]/div/div[2]/a[3]
/html/body/div[1]/div[1]/div/div[3]/a[1]
/html/body/div[1]/div[1]/div/div[3]/a[2]
/html/body/div[1]/div[1]/div/div[3]/a[3]
/html/body/div[1]/div[1]/div/div[3]/a[4]
/html/body/div[1]/div[1]/div/div[3]/a[5]
/html/body/div[1]/div[1]/div/div[3]/a[6]
/html/body/div[1]/div[1]/div/div[3]/a[7]
/html/body/div[1]/div[1]/div/div[3]/a[8]
/html/body/div[1]/div[1]/div/div[3]/a[9]
/html/body/div[1]/div[2]/a[1]
/html/body/div[1]/div[2]/a[2]
/html/body/div[1]/div[2]/a[3]
/html/body/div[1]/div[2]/a[4]
/html/body/div[1]/div[2]/a[5]
/html/body/div[1]/div[2]/a[6]
/html/body/div[1]/div[2]/a[7]
/html/body/div[1]/div[2]/a[8]
/html/body/div[1]/div[2]/a[9]
/html/body/div[1]/div[3]/div/div/div[1]
/html/body/div[1]/div[3]/div/div/div[2]/p
/html/body/div[1]/div[4]/div/div/p[1]/a[1]
/html/body/div[1]/div[4]/div/div/p[1]/a[2]
/html/body/div[1]/div[4]/div/div/p[1]/a[3]
/html/body/div[1]/div[4]/div/div/p[1]/a[4]
/html/body/div[1]/div[4]/div/div/p[2]/a[1]
/html/body/div[1]/div[4]/div/div/p[2]/a[2]
/html/body/div[1]/div[4]/div/div/p[2]/a[3]
/html/body/div[1]/div[5]
/html/body/div[2]
/html/body/div[3]
/html/body/div[4]