使用 XPath 搜尋 XML
從版本 2.7 開始,ElementTree
對 XPath 查詢有更好的支援。XPath 是一種語法,使你能夠在 xml 中導航,就像用於搜尋資料庫的 SQL 一樣。find
和 findall
函式都支援 XPath。下面的 xml 將用於此示例
<Catalog>
<Books>
<Book id="1" price="7.95">
<Title>Do Androids Dream of Electric Sheep?</Title>
<Author>Philip K. Dick</Author>
</Book>
<Book id="5" price="5.95">
<Title>The Colour of Magic</Title>
<Author>Terry Pratchett</Author>
</Book>
<Book id="7" price="6.95">
<Title>The Eye of The World</Title>
<Author>Robert Jordan</Author>
</Book>
</Books>
</Catalog>
搜尋所有書籍:
import xml.etree.cElementTree as ET
tree = ET.parse('sample.xml')
tree.findall('Books/Book')
搜尋標題為’‘魔法的顏色’的書:
tree.find("Books/Book[Title='The Colour of Magic']")
# always use '' in the right side of the comparison
搜尋 id = 5 的書:
tree.find("Books/Book[@id='5']")
# searches with xml attributes must have '@' before the name
搜尋第二本書:
tree.find("Books/Book[2]")
# indexes starts at 1, not 0
搜尋最後一本書:
tree.find("Books/Book[last()]")
# 'last' is the only xpath function allowed in ElementTree
搜尋所有作者:
tree.findall(".//Author")
#searches with // must use a relative path