Resolving a relative url path to its absolute path

Yes, there is urlparse.urljoin, or urllib.parse.urljoin for Python 3.

>>> try: from urlparse import urljoin # Python2
... except ImportError: from urllib.parse import urljoin # Python3
...
>>> 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'

for copy-and-paste:

try:
    from urlparse import urljoin  # Python2
except ImportError:
    from urllib.parse import urljoin  # Python3