[David Bremner <david@tethera.net>]

Floris wrote: 
> FWIW having spaces between the function name and parentheses is rather
>uncommon for python style.  Though of course complaining about style
>without using an auto-formatter is pretty meh these days :)
>

Yeah fair enough, it's the default in the C code, but we pretty
clearly have different styles going on in different languages.

>> +            val_p = capi.lib.notmuch_config_pairs_value (super()._iter_p)
>> +            key_p = capi.lib.notmuch_config_pairs_key (super()._iter_p)
>> +            key = base.BinString.from_cffi(key_p)
>
>does key_p need a NULL check first or can it never be NULL?

I think it can never be NULL, but if it is, better to raise an exception I think.

>>      def test_iter(self, db):
>> -        assert list(db.config) == []
>> -        db.config['spam'] = 'ham'
>> -        db.config['eggs'] = 'bacon'
>> -        assert set(db.config) == {'spam', 'eggs'}
>> -        assert set(db.config.keys()) == {'spam', 'eggs'}
>> -        assert set(db.config.values()) == {'ham', 'bacon'}
>> -        assert set(db.config.items()) == {('spam', 'ham'), ('eggs', 'bacon')}
>> +        import re
>> +        prefix = re.compile(r"^TEST[.]")
>> +        assert [ x for x in list(db.config) if prefix.match(x) ] == []
>
>`x.startswith('TEST.')` is probably lighter weight here, maybe easier to
>read too that's subjective i guess
>
>You can even try something like this to further make it more readable:
>
>has_prefix = lambda x: x.startswith('TEST.')

I did variation on this, defining an inner function instead of using a lambda.

>
>> +        db.config['TEST.spam'] = 'TEST.ham'
>> +        db.config['TEST.eggs'] = 'TEST.bacon'
>> +        assert { x for x in set(db.config) if prefix.match(x) } == {'TEST.spam', 'TEST.eggs'}
>> +        assert { x for x in set(db.config.keys()) if prefix.match (x) } == {'TEST.spam', 'TEST.eggs'}
>
>I'm not sure why you need to wrap `db.config.keys()` in `set()`?  This
>explicitly creates a set out of things before turning it back into an
>interator while you're fine with the original iterator I think?

Good question. That seems to apply to list(db.config) above also?