Note that I have a patch pending re Wikia family at https://gerrit.wikimedia.org/r/#/c/171616/ , and more to come

(In reply to John Mark Vandenberg from comment #0)

However Wikia has a redirect on the server from /wiki/ to / for those sites.

However the /wiki/ is needed for some sites.

http://cs.wow.wikia.com/wiki/Hlavn%C3%AD_strana works

But http://cs.wow.wikia.com/Hlavn%C3%AD_strana redirects to
http://cs.wow.wikia.com/wiki/Speci%C3%A1ln%C3%AD:Our

So keeping the nicepath as /wiki/ is necessary, and we have to hope Wikia
has redirects in place for all wikis where the wiki nice titles are not
located at /wiki/Foo

Yep, we do. There are only about 26 or so wikis on Wikia that use short URLs without the /wiki/, the rest all use the standard /wiki/$1 article path. All those that do have short URLs have redirects from /wiki/.

In T75137#770709, @Grunny wrote:

(In reply to John Mark Vandenberg from comment #0)

However Wikia has a redirect on the server from /wiki/ to / for those sites.

However the /wiki/ is needed for some sites.

http://cs.wow.wikia.com/wiki/Hlavn%C3%AD_strana works

But http://cs.wow.wikia.com/Hlavn%C3%AD_strana redirects to
http://cs.wow.wikia.com/wiki/Speci%C3%A1ln%C3%AD:Our

So keeping the nicepath as /wiki/ is necessary, and we have to hope Wikia
has redirects in place for all wikis where the wiki nice titles are not
located at /wiki/Foo

Yep, we do. There are only about 26 or so wikis on Wikia that use short URLs without the /wiki/, the rest all use the standard /wiki/$1 article path. All those that do have short URLs have redirects from /wiki/.

http://lyrics.wikia.com/wiki/Category:Artists_A and http://wowwiki.wikia.com/wiki/Portal:Main now use a /wiki/ nicepath.

The main website (http://www.wikia.com/) appears to still have a nicepath of ''.

How many wikis now still have a nicepath of '' ?
It might be small enough list that Pywikibot can use an explicit exception list on the client site, so that our nicepath is always correct.

The codebase says that the function nicepath() is deprecated, and it is not being used by any of the scripts as of now in the scripts/. The only function using this in core is nice_get_address() ... which is also deprecated.

Are nicepath() and nice_get_address() still needed ? Doesn't seem like anything is using it.
If it's still needed and only an exception list is requried then we can tag this with good first task