How can I check if a URL is absolute using Python?

Question

What is the preferred solution for checking if an URL is relative or absolute?

Answer 1

If you want to know if an URL is absolute or relative in order to join it with a base URL, I usually do urlparse.urljoin anyway:

>>> from urlparse import urljoin
>>> urljoin('http://example.com/', 'http://example.com/picture.png')
'http://example.com/picture.png'
>>> urljoin('http://example1.com/', '/picture.png')
'http://example1.com/picture.png'
>>>