Wildhost

Checks wildcard domain names.

Install

pip install wildhost

Usage

Import the module

>>> import wildhost

Pass a hostname to the check function.

>>> wildhost.check('foo.bar.domain.tld')

If none of the levels of the name are wildcards, None will be returned.

>>> wildhost.check('mail.google.com')

This returns None as neither google.com nor mail.google.com are wildcards.

For a wildcard name, the lowest level wildcard name will be returned.

>>> wildhost.check('foo.bar.spam.grok.sharefile.com')
'sharefile.com'

Performance

The module caches the wildcard results and uses them in further checks. For example:

>>> wildhost.check('foo.bar.spam.grok.sharefile.com')  # this will be a fresh check
'sharefile.com'
>>> wildhost.check('boom.blast.sharefile.com')  # this will use the cache
'sharefile.com'

Once sharefile.com is known to be a wildcard, any further subdomains of sharefile.com will be evaluated as wildcards as well. This is determined from a static check and therefore very fast.

However, there is a caveat. In an unlikely scenario, api.sharefile.com will be missed, if it happens to be a valid subdomain.

In such cases, when in doubt, use the wildcard.check_fresh function to ignore the cache.

>>> wildcard.check_fresh('api.sharefile.com')

This will return None if it is, in fact, not a wildcard.

check_fresh needs to make network requests, where as check caches the results and is very fast. Choose one that is suitable for the problem at hand.