使用URLJOIN從相對路徑獲取絕對路徑：
>>> from urlparse import urljoin
>>> urljoin("http://www.asite.com/folder/currentpage.html", "anotherpage.html")
'http://www.asite.com/folder/anotherpage.html'
>>> urljoin("http://www.asite.com/folder/currentpage.html", "folder2/anotherpage.html")
'http://www.asite.com/folder/folder2/anotherpage.html'
>>> urljoin("http://www.asite.com/folder/currentpage.html", "/folder3/anotherpage.html")
'http://www.asite.com/folder3/anotherpage.html'
>>> urljoin("http://www.asite.com/folder/currentpage.html", "../finalpage.html")
'http://www.asite.com/finalpage.html'