furl produces invalid urls about furl HOT 3 CLOSED

Furl is doing the correct thing here, though it can be slightly confusing at
first glance.

The confusion boils down to how -- in the absence of URL delimiters (e.g. ://,
/, ?, etc) -- solitary strings like www.example.com are parsed.

While www.example.com looks like a host to you and me, how does furl know it's
a host? What about

>>> furl('localhost')

Is localhost a host, too? Or is it a path? Remember host strings can be almost
anything -- they needn't contain periods (e.g. localhost). That, and every
valid host string is also a valid path segment.
http://foo.com/url/www.example.com/ is a perfectly valid URL, too.

So, to be consistent, furl parses all single-component strings (strings without
multiple URL components separated by URL delimiters) as path strings. You can
see this behavior with www.example.com above.

>>> f = furl('www.example.com')
>>> f.host
None
>>> f.path.segments
['www.example.com']

This is also the exact behavior of Python's built-in urlparse module, too.

>>> from urlparse import urlparse
>>> urlparse('www.example.com')
ParseResult(scheme='', netloc='', path='www.example.com', params='', query='', fragment='')

Back to your original example. There are three slashes (///) in the final URL
because www.example.com is parsed as a path segment and not a host.

>>> f = furl('www.example.com').set(scheme='http').add(path='test/path')
>>> f.path.segments
['www.example.com', 'test', 'path']
>>> f.host
None

If you want furl to adopt www.example.com as the host, explicitly set it as
the host with set(). Like

>>> f = furl().set(host='www.example.com', scheme='http').add(path='test/path')
>>> f.path.segments
['test', 'path']
>>> f.host
'www.example.com'

I've thought about adding the ability for furl to 'guess' whether a solitary
string is the host string or a path segment based on whether or not that string
contains periods, but that would lead to inconsistent behavior. Consistent
behavior, even if sometimes initially surprising, is better behavior.

Does that answer your original question?

from furl.

Yes, absolutely. Thanks a lot for your very comprehensive answer.

from furl.

Wonderful.

Thank you for bringing this question to my attention, Max. Don't hesitate to let
me know if there's anything I can do for you.

from furl.