這是Beautiful Soup 4.2.1 中新增的方法 · Beautiful Soup 4.2.0 中文文檔

# 這是Beautiful Soup 4.2.1 中新增的方法創建一個tag最好的方法是調用工廠方法 `BeautifulSoup.new_tag()` : ``` soup = BeautifulSoup("") original_tag = soup.b new_tag = soup.new_tag("a", href="http://www.example.com") original_tag.append(new_tag) original_tag # <a href="http://www.example.com"></a> new_tag.string = "Link text." original_tag # <a href="http://www.example.com">Link text.</a> ``` 第一個參數作為tag的name,是必填,其它參數選填 ## insert() `Tag.insert()` 方法與 `Tag.append()` 方法類似,區別是不會把新元素添加到父節點 `.contents` 屬性的最后,而是把元素插入到指定的位置.與Python列表總的 `.insert()` 方法的用法下同: ``` markup = '<a href="http://example.com/">I linked to example.com</a>' soup = BeautifulSoup(markup) tag = soup.a tag.insert(1, "but did not endorse ") tag # <a href="http://example.com/">I linked to but did not endorse example.com</a> tag.contents # [u'I linked to ', u'but did not endorse', example.com] ``` ## insert_before() 和 insert_after() `insert_before()` 方法在當前tag或文本節點前插入內容: ``` soup = BeautifulSoup("stop") tag = soup.new_tag("i") tag.string = "Don't" soup.b.string.insert_before(tag) soup.b # Don'tstop ``` `insert_after()` 方法在當前tag或文本節點后插入內容: ``` soup.b.i.insert_after(soup.new_string(" ever ")) soup.b # Don't ever stop soup.b.contents # [Don't, u' ever ', u'stop'] ``` ## clear() `Tag.clear()` 方法移除當前tag的內容: ``` markup = '<a href="http://example.com/">I linked to example.com</a>' soup = BeautifulSoup(markup) tag = soup.a tag.clear() tag # <a href="http://example.com/"></a> ``` ## extract() `PageElement.extract()` 方法將當前tag移除文檔樹,并作為方法結果返回: ``` markup = '<a href="http://example.com/">I linked to example.com</a>' soup = BeautifulSoup(markup) a_tag = soup.a i_tag = soup.i.extract() a_tag # <a href="http://example.com/">I linked to</a> i_tag # example.com print(i_tag.parent) None ``` 這個方法實際上產生了2個文檔樹: 一個是用來解析原始文檔的 `BeautifulSoup` 對象,另一個是被移除并且返回的tag.被移除并返回的tag可以繼續調用 `extract` 方法: ``` my_string = i_tag.string.extract() my_string # u'example.com' print(my_string.parent) # None i_tag # ``` ## decompose() `Tag.decompose()` 方法將當前節點移除文檔樹并完全銷毀: ``` markup = '<a href="http://example.com/">I linked to example.com</a>' soup = BeautifulSoup(markup) a_tag = soup.a soup.i.decompose() a_tag # <a href="http://example.com/">I linked to</a> ``` ## replace_with() `PageElement.replace_with()` 方法移除文檔樹中的某段內容,并用新tag或文本節點替代它: ``` markup = '<a href="http://example.com/">I linked to example.com</a>' soup = BeautifulSoup(markup) a_tag = soup.a new_tag = soup.new_tag("b") new_tag.string = "example.net" a_tag.i.replace_with(new_tag) a_tag # <a href="http://example.com/">I linked to example.net</a> ``` `replace_with()` 方法返回被替代的tag或文本節點,可以用來瀏覽或添加到文檔樹其它地方 ## wrap() `PageElement.wrap()` 方法可以對指定的tag元素進行包裝 \[8\] ,并返回包裝后的結果: ``` soup = BeautifulSoup("I wish I was bold.") soup.p.string.wrap(soup.new_tag("b")) # I wish I was bold. soup.p.wrap(soup.new_tag("div")) # I wish I was bold. ``` 該方法在 Beautiful Soup 4.0.5 中添加 ## unwrap() `Tag.unwrap()` 方法與 `wrap()` 方法相反.將移除tag內的所有tag標簽,該方法常被用來進行標記的解包: ``` markup = '<a href="http://example.com/">I linked to example.com</a>' soup = BeautifulSoup(markup) a_tag = soup.a a_tag.i.unwrap() a_tag # <a href="http://example.com/">I linked to example.com</a> ``` 與 `replace_with()` 方法相同, `unwrap()` 方法返回被移除的tag