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本篇內容介紹了“Python xpath,JsonPath,bs4怎么使用”的有關知識,在實際案例的操作過程中,不少人都會遇到這樣的困境,接下來就讓小編帶領大家學習一下如何處理這些情況吧!希望大家仔細閱讀,能夠學有所成!
google提前安裝xpath插件,按ctrl + shift + x 出現小黑框
安裝lxml庫 pip install lxml ‐i https://pypi.douban.com/simple
導入lxml.etreefrom lxml import etree
etree.parse() 解析本地文件html_tree = etree.parse('XX.html')
etree.HTML() 服務器響應文件html_tree = etree.HTML(response.read().decode('utf‐8')
.html_tree.xpath(xpath路徑)
1.路徑查詢
查找所有子孫節點,不考慮層級關系
找直接子節點
2.謂詞查詢
//div[@id] //div[@id="maincontent"]
3.屬性查詢
//@class
4.模糊查詢
//div[contains(@id, "he")] //div[starts‐with(@id, "he")]
5.內容查詢
//div/h2/text()
6.邏輯運算
//div[@id="head" and @class="s_down"] //title | //price
xpath.html
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"/> <title>Title</title> </head> <body> <ul> <li id="l1" class="class1">北京</li> <li id="l2" class="class2">上海</li> <li id="d1">廣州</li> <li>深圳</li> </ul> </body> </html>
from lxml import etree # xpath解析 # 本地文件: etree.parse # 服務器相應的數據 response.read().decode('utf-8') etree.HTML() tree = etree.parse('xpath.html') # 查找url下邊的li li_list = tree.xpath('//body/ul/li') print(len(li_list)) # 4 # 獲取標簽中的內容 li_list = tree.xpath('//body/ul/li/text()') print(li_list) # ['北京', '上海', '廣州', '深圳'] # 獲取帶id屬性的li li_list = tree.xpath('//ul/li[@id]') print(len(li_list)) # 3 # 獲取id為l1的標簽內容 li_list = tree.xpath('//ul/li[@id="l1"]/text()') print(li_list) # ['北京'] # 獲取id為l1的class屬性值 c1 = tree.xpath('//ul/li[@id="l1"]/@class') print(c1) # ['class1'] # 獲取id中包含l的標簽 li_list = tree.xpath('//ul/li[contains(@id, "l")]/text()') print(li_list) # ['北京', '上海'] # 獲取id以d開頭的標簽 li_list = tree.xpath('//ul/li[starts-with(@id,"d")]/text()') print(li_list) # ['廣州'] # 獲取id為l2并且class為class2的標簽 li_list = tree.xpath('//ul/li[@id="l2" and @class="class2"]/text()') print(li_list) # ['上海'] # 獲取id為l2或id為d1的標簽 li_list = tree.xpath('//ul/li[@id="l2"]/text() | //ul/li[@id="d1"]/text()') print(li_list) # ['上海', '廣州']
import urllib.request from lxml import etree url = 'http://www.baidu.com' headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36' } request = urllib.request.Request(url=url, headers=headers) response = urllib.request.urlopen(request) content = response.read().decode('utf-8') tree = etree.HTML(content) value = tree.xpath('//input[@id="su"]/@value') print(value)
1.5 爬取站長素材的圖片
# 需求 下載的前十頁的圖片 # https://sc.chinaz.com/tupian/qinglvtupian.html 1 # https://sc.chinaz.com/tupian/qinglvtupian_page.html import urllib.request from lxml import etree def create_request(page): if (page == 1): url = 'https://sc.chinaz.com/tupian/qinglvtupian.html' else: url = 'https://sc.chinaz.com/tupian/qinglvtupian_' + str(page) + '.html' headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Safari/537.36', } request = urllib.request.Request(url=url, headers=headers) return request def get_content(request): response = urllib.request.urlopen(request) content = response.read().decode('utf-8') return content def down_load(content): # 下載圖片 # urllib.request.urlretrieve('圖片地址','文件的名字') tree = etree.HTML(content) name_list = tree.xpath('//div[@id="container"]//a/img/@alt') # 一般設計圖片的網站都會進行懶加載 src_list = tree.xpath('//div[@id="container"]//a/img/@src2') print(src_list) for i in range(len(name_list)): name = name_list[i] src = src_list[i] url = 'https:' + src urllib.request.urlretrieve(url=url, filename='./loveImg/' + name + '.jpg') if __name__ == '__main__': start_page = int(input('請輸入起始頁碼')) end_page = int(input('請輸入結束頁碼')) for page in range(start_page, end_page + 1): # (1) 請求對象的定制 request = create_request(page) # (2)獲取網頁的源碼 content = get_content(request) # (3)下載 down_load(content)
pip install jsonpath
obj = json.load(open('json文件', 'r', encoding='utf‐8')) ret = jsonpath.jsonpath(obj, 'jsonpath語法')
JSONPath語法元素和對應XPath元素的對比:
示例:
jsonpath.json
{ "store": { "book": [ { "category": "修真", "author": "六道", "title": "壞蛋是怎樣練成的", "price": 8.95 }, { "category": "修真", "author": "天蠶土豆", "title": "斗破蒼穹", "price": 12.99 }, { "category": "修真", "author": "唐家三少", "title": "斗羅大陸", "isbn": "0-553-21311-3", "price": 8.99 }, { "category": "修真", "author": "南派三叔", "title": "星辰變", "isbn": "0-395-19395-8", "price": 22.99 } ], "bicycle": { "author": "老馬", "color": "黑色", "price": 19.95 } } }
import json import jsonpath obj = json.load(open('jsonpath.json', 'r', encoding='utf-8')) # 書店所有書的作者 author_list = jsonpath.jsonpath(obj, '$.store.book[*].author') print(author_list) # ['六道', '天蠶土豆', '唐家三少', '南派三叔'] # 所有的作者 author_list = jsonpath.jsonpath(obj, '$..author') print(author_list) # ['六道', '天蠶土豆', '唐家三少', '南派三叔', '老馬'] # store下面的所有的元素 tag_list = jsonpath.jsonpath(obj, '$.store.*') print( tag_list) # [[{'category': '修真', 'author': '六道', 'title': '壞蛋是怎樣練成的', 'price': 8.95}, {'category': '修真', 'author': '天蠶土豆', 'title': '斗破蒼穹', 'price': 12.99}, {'category': '修真', 'author': '唐家三少', 'title': '斗羅大陸', 'isbn': '0-553-21311-3', 'price': 8.99}, {'category': '修真', 'author': '南派三叔', 'title': '星辰變', 'isbn': '0-395-19395-8', 'price': 22.99}], {'author': '老馬', 'color': '黑色', 'price': 19.95}] # store里面所有東西的price price_list = jsonpath.jsonpath(obj, '$.store..price') print(price_list) # [8.95, 12.99, 8.99, 22.99, 19.95] # 第三個書 book = jsonpath.jsonpath(obj, '$..book[2]') print(book) # [{'category': '修真', 'author': '唐家三少', 'title': '斗羅大陸', 'isbn': '0-553-21311-3', 'price': 8.99}] # 最后一本書 book = jsonpath.jsonpath(obj, '$..book[(@.length-1)]') print(book) # [{'category': '修真', 'author': '南派三叔', 'title': '星辰變', 'isbn': '0-395-19395-8', 'price': 22.99}] # 前面的兩本書 book_list = jsonpath.jsonpath(obj, '$..book[0,1]') # book_list = jsonpath.jsonpath(obj,'$..book[:2]') print( book_list) # [{'category': '修真', 'author': '六道', 'title': '壞蛋是怎樣練成的', 'price': 8.95}, {'category': '修真', 'author': '天蠶土豆', 'title': '斗破蒼穹', 'price': 12.99}] # 條件過濾需要在()的前面添加一個? # 過濾出所有的包含isbn的書。 book_list = jsonpath.jsonpath(obj, '$..book[?(@.isbn)]') print( book_list) # [{'category': '修真', 'author': '唐家三少', 'title': '斗羅大陸', 'isbn': '0-553-21311-3', 'price': 8.99}, {'category': '修真', 'author': '南派三叔', 'title': '星辰變', 'isbn': '0-395-19395-8', 'price': 22.99}] # 哪本書超過了10塊錢 book_list = jsonpath.jsonpath(obj, '$..book[?(@.price>10)]') print( book_list) # [{'category': '修真', 'author': '天蠶土豆', 'title': '斗破蒼穹', 'price': 12.99}, {'category': '修真', 'author': '南派三叔', 'title': '星辰變', 'isbn': '0-395-19395-8', 'price': 22.99}]
1.安裝
pip install bs4
2.導入
from bs4 import BeautifulSoup
3.創建對象
服務器響應的文件生成對象 soup = BeautifulSoup(response.read().decode(), 'lxml')
本地文件生成對象 soup = BeautifulSoup(open('1.html'), 'lxml')
注意:默認打開文件的編碼格式gbk所以需要指定打開編碼格式utf-8
1.根據標簽名查找節點 soup.a 【注】只能找到第一個a soup.a.name soup.a.attrs 2.函數 (1).find(返回一個對象) find('a'):只找到第一個a標簽 find('a', title='名字') find('a', class_='名字') (2).find_all(返回一個列表) find_all('a') 查找到所有的a find_all(['a', 'span']) 返回所有的a和span find_all('a', limit=2) 只找前兩個a (3).select(根據選擇器得到節點對象)【推薦】 1.element eg:p 2..class eg:.firstname 3.#id eg:#firstname 4.屬性選擇器 [attribute] eg:li = soup.select('li[class]') [attribute=value] eg:li = soup.select('li[class="hengheng1"]') 5.層級選擇器 element element div p element>element div>p element,element div,p eg:soup = soup.select('a,span')
1.根據標簽名查找節點 soup.a 【注】只能找到第一個a soup.a.name soup.a.attrs 2.函數 (1).find(返回一個對象) find('a'):只找到第一個a標簽 find('a', title='名字') find('a', class_='名字') (2).find_all(返回一個列表) find_all('a') 查找到所有的a find_all(['a', 'span']) 返回所有的a和span find_all('a', limit=2) 只找前兩個a (3).select(根據選擇器得到節點對象)【推薦】 1.element eg:p 2..class eg:.firstname 3.#id eg:#firstname 4.屬性選擇器 [attribute] eg:li = soup.select('li[class]') [attribute=value] eg:li = soup.select('li[class="hengheng1"]') 5.層級選擇器 element element div p element>element div>p element,element div,p eg:soup = soup.select('a,span')
(1).獲取節點內容:適用于標簽中嵌套標簽的結構 obj.string obj.get_text()【推薦】 (2).節點的屬性 tag.name 獲取標簽名 eg:tag = find('li) print(tag.name) tag.attrs將屬性值作為一個字典返回 (3).獲取節點屬性 obj.attrs.get('title')【常用】 obj.get('title') obj['title']
(1).獲取節點內容:適用于標簽中嵌套標簽的結構 obj.string obj.get_text()【推薦】 (2).節點的屬性 tag.name 獲取標簽名 eg:tag = find('li) print(tag.name) tag.attrs將屬性值作為一個字典返回 (3).獲取節點屬性 obj.attrs.get('title')【常用】 obj.get('title') obj['title']
bs4.html
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <div> <ul> <li id="l1">張三</li> <li id="l2">李四</li> <li>王五</li> <a href="" id=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" " class="a1">google</a> <span>嘿嘿嘿</span> </ul> </div> <a href="" title=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" a2">百度</a> <div id="d1"> <span> 哈哈哈 </span> </div> <p id="p1" class="p1">呵呵呵</p> </body> </html>
from bs4 import BeautifulSoup # 通過解析本地文件 來將bs4的基礎語法進行講解 # 默認打開的文件的編碼格式是gbk 所以在打開文件的時候需要指定編碼 soup = BeautifulSoup(open('bs4.html', encoding='utf-8'), 'lxml') # 根據標簽名查找節點 # 找到的是第一個符合條件的數據 print(soup.a) # <a class="a1" href="" id=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ">google</a> # 獲取標簽的屬性和屬性值 print(soup.a.attrs) # {'href': '', 'id': '', 'class': ['a1']} # bs4的一些函數 # (1)find # 返回的是第一個符合條件的數據 print(soup.find('a')) # <a class="a1" href="" id=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ">google</a> # 根據title的值來找到對應的標簽對象 print(soup.find('a', title="a2")) # <a href="" title=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" a2">百度</a> # 根據class的值來找到對應的標簽對象 注意的是class需要添加下劃線 print(soup.find('a', class_="a1")) # <a class="a1" href="" id=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ">google</a> # (2)find_all 返回的是一個列表 并且返回了所有的a標簽 print(soup.find_all('a')) # [<a class="a1" href="" id=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ">google</a>, <a href="" title=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" a2">百度</a>] # 如果想獲取的是多個標簽的數據 那么需要在find_all的參數中添加的是列表的數據 print(soup.find_all(['a','span'])) # [<a class="a1" href="" id=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ">google</a>, <span>嘿嘿嘿</span>, <a href="" title=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" a2">百</a><spa哈</span>] # limit的作用是查找前幾個數據 print(soup.find_all('li', limit=2)) # [<li id="l1">張三</li>, <li id="l2">李四</li>] # (3)select(推薦) # select方法返回的是一個列表 并且會返回多個數據 print(soup.select('a')) # [<a class="a1" href="" id=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ">google</a>, <a href="" title=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" a2">百度</a>] # 可以通過.代表class 我們把這種操作叫做類選擇器 print(soup.select('.a1')) # [<a class="a1" href="" id=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ">google</a>] print(soup.select('#l1')) # [<li id="l1">張三</li>] # 屬性選擇器---通過屬性來尋找對應的標簽 # 查找到li標簽中有id的標簽 print(soup.select('li[id]')) # [<li id="l1">張三</li>, <li id="l2">李四</li>] # 查找到li標簽中id為l2的標簽 print(soup.select('li[id="l2"]')) # [<li id="l2">李四</li>] # 層級選擇器 # 后代選擇器 # 找到的是div下面的li print(soup.select('div li')) # [<li id="l1">張三</li>, <li id="l2">李四</li>, <li>王五</li>] # 子代選擇器 # 某標簽的第一級子標簽 # 注意:很多的計算機編程語言中 如果不加空格不會輸出內容 但是在bs4中 不會報錯 會顯示內容 print(soup.select('div > ul > li')) # [<li id="l1">張三</li>, <li id="l2">李四</li>, <li>王五</li>] # 找到a標簽和li標簽的所有的對象 print(soup.select( 'a,li')) # [<li id="l1">張三</li>, <li id="l2">李四</li>, <li>王五</li>, <a class="a1" href="" id=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ">google</a>, <a href="" title=" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" a2">百度</a>] # 節點信息 # 獲取節點內容 obj = soup.select('#d1')[0] # 如果標簽對象中 只有內容 那么string和get_text()都可以使用 # 如果標簽對象中 除了內容還有標簽 那么string就獲取不到數據 而get_text()是可以獲取數據 # 我們一般情況下 推薦使用get_text() print(obj.string) # None print(obj.get_text()) # 哈哈哈 # 節點的屬性 obj = soup.select('#p1')[0] # name是標簽的名字 print(obj.name) # p # 將屬性值左右一個字典返回 print(obj.attrs) # {'id': 'p1', 'class': ['p1']} # 獲取節點的屬性 obj = soup.select('#p1')[0] # print(obj.attrs.get('class')) # ['p1'] print(obj.get('class')) # ['p1'] print(obj['class']) # ['p1']
import urllib.request url = 'https://www.starbucks.com.cn/menu/' response = urllib.request.urlopen(url) content = response.read().decode('utf-8') from bs4 import BeautifulSoup soup = BeautifulSoup(content,'lxml') # //ul[@class="grid padded-3 product"]//strong/text() # 一般先用xpath方式通過google插件寫好解析的表達式 name_list = soup.select('ul[class="grid padded-3 product"] strong') for name in name_list: print(name.get_text())
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