官網:https://www.crummy.com/software/BeautifulSoup/bs4/doc/css
參考:http://www.javashuo.com/article/p-bhmtmues-cu.htmlhtml
什麼是BeautifulSoup?函數
BeautifulSoup是用Python寫的一個HTML/XML的解析器,它能夠很好的處理不規範標記並生成剖析樹(parse tree)。 它提供簡單又經常使用的導航(navigating),搜索以及修改剖析樹的操做。測試
下面經過一個測試例子簡單說明下BeautifulSoup的用法spa
def beautifulSoup_test(self): html_doc = """ <html><head><title>The Dormouse's story</title></head> <body> <p class="title"><b>The Dormouse's story</b></p> <p class="story">Once upon a time there were three little sisters; and their names were <a href="http://example.com/elsie" class="sister" id="link1">Elsie</a>, <a href="http://example.com/lacie" class="sister" id="link2">Lacie</a> and <a href="http://example.com/tillie" class="sister" id="link3">Tillie</a>; <div class="text" id="div1">測試</div> and they lived at the bottom of a well.</p> <p class="story">...</p> """ # soup 就是BeautifulSoup處理格式化後的字符串 soup = BeautifulSoup(html_doc,'lxml') # 獲得的是title標籤 print(soup.title) # 輸出:<title>The Dormouse's story</title> # 獲得的是文檔中的第一個p標籤,要想獲得全部標籤,得用find_all函數。 # find_all 函數返回的是一個序列,能夠對它進行循環,依次獲得想到的東西. print(soup.p) print(soup.find_all('p')) print(soup.find(id='link3')) # 是返回文本,這個對每個BeautifulSoup處理後的對象獲得的標籤都是生效的 print(soup.get_text()) aitems = soup.find_all('a') # 獲取標籤a的連接和id for item in aitems: print(item["href"],item["id"]) # 一、經過css查找 print(soup.find_all("a", class_="sister")) # 輸出:[<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>, # <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>, # <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>] print(soup.select("p.title")) # 輸出:[<p class="title"><b>The Dormouse's story</b></p>] # 二、經過屬性進行查找 print(soup.find_all("a", attrs={"class": "sister"})) #輸出:[<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>, # <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>, # <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>] # 三、經過文本進行查找 print(soup.find_all(text="Elsie")) # 輸出:['Elsie'] print(soup.find_all(text=["Tillie", "Elsie", "Lacie"])) # 輸出:['Elsie', 'Lacie', 'Tillie'] # 四、限制結果個數 print(soup.find_all("a", limit=2)) #輸出:[<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>, # <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>] print(soup.find_all(id="link2")) # [<a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>] print(soup.find_all(id=True)) #輸出:[<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>, # 輸出:<a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>, # <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>, # <div class="text" id="div1">測試</div>]