Splitting URLs

[Tim Chase]

> URL = 'http://steve:secret@www.domain.com.au:82/dir" + \
>     'ectory/file.html;params?query#fragment'
> 
> If I split the URL, I would like to get the following components:
> 
> scheme = 'http'
> netloc = 'steve:secret at www.domain.com.au:82'
> username = 'steve'
> password = 'secret'
> hostname = 'www.domain.com.au'
> port = 82
> path = '/directory/file.html'
> parameters = 'params'
> query = 'query'
> fragment = 'fragment'
> 
> I can get *most* of the way with urlparse.urlparse: it will split the URL 
> into a tuple:
> 
> ('http', 'steve:secret at www.domain.com.au:82', '/directory/file.html', 
> 'params', 'query', 'fragment')
> 
> If I'm using Python 2.5, I can split the netloc field further with named 
> attributes. Unfortunately, I can't rely on Python 2.5 (for my sins I have 
> to support 2.4). Before I write code to split the netloc field by hand (a 
> nuisance, but doable) I thought I'd ask if there was a function somewhere 
> in the standard library I had missed.

there are some goodies in urllib for doing some of this
splitting.  Example code at the bottom of my reply (though it
seems to choke on certain protocols such as "mailto:" and "ssh:"
because urlparse doesn't return the netloc properly)

> This second question isn't specifically Python related, but I'm asking it 
> anyway...
> 
> I'd also like to split the domain part of a HTTP netloc into top level 
> domain (.au), second level (.com), etc. I don't need to validate the TLD, 
> I just need to split it. Is splitting on dots sufficient, or will that 
> miss some odd corner case of the HTTP specification?

I believe that dots are the sanctioned separator, HOWEVER, you
can have a non-qualified machine-name with local scope, so you
can easily have NO TLD, such as

  http://user:password@localhost:8000/path/to/thing

There's also the ambiguity of what "TLD" means if you use IP
addresses:

 http://user:password@192.168.1.1:8000/path/to/thing

Does that make the TLD "1"?  Other odd edge-cases that are
usually allowable (but frowned upon, mostly used by
spammers/phishers) include using a long-int as the domain-name,
such as

  http://user:password@2130706433:8000/path/to/thing

In an attempt to play with these functions, I present the code below.

-tkc


import urlparse, urllib
tests = (
  'http://steve:secret@www.example.com.au:82/'
    'directory/file.html;params?query#fragment',
  'http://user:password@192.168.1.2/path/to/thing/',
  'http://192.168.1.2/path/to/thing/',
  'http://2130706433/path/to/thing/',
  'http://localhost/path/to/thing/',
  'http://user:password@localhost/path/to/thing/',
  'telnet://foo@bar.com',
  'ssh://user@example.com',
  'gopher://wais.example.edu',
  'svn+ssh://user:password@svn.example.com/svn/here/there/',
  'mailto:joe at example.com',
  )

def is_ip_address(s):
  for i, part in enumerate(s.split('.')):
    try:
      assert 0 <= int(i) <= 255
    except:
      return False
  return i == 3

def steve_parse(url):
  (scheme, netloc, path,
    params, query, fragment) = urlparse.urlparse(url)
  creds, host = urllib.splituser(netloc)
  username, password = urllib.splitpasswd(creds or '')
  host, port = urllib.splitport(host)
  if '.' in host and not is_ip_address(host):
      domain, tld = host.rsplit('.', 1)
  else:
    domain = host
    tld = ''
  return (
    scheme, username, password,
    domain, tld, port,
    path, params, query,
    fragment)
if __name__ == '__main__':
  for test in tests:
    print test
    (scheme, username, password,
      domain, tld, port,
      path, params, query,
      fragment) = steve_parse(test)
    print '\tScheme: ', scheme
    print '\tUsername: ', username
    print '\tPassword: ', password
    print '\tDomain: ', domain
    print '\tTLD: ', tld
    print '\tPort: ', port
    print '\tPath: ', path
    print '\tParams: ', params
    print '\tQuery: ', query
    print '\tFragment: ', fragment
    print '='*50