I’m trying to convert a sql code to python, have added the sqlfiddle here

This link has the input & expected output along with sql code as below:

select a.id, b.country, a.person, b.num
from tab2 a
left join tab1 b
on a.id=b.id
WHERE
case when b.country = 'Denmark' then 'Swiz' 
else b.country
end <> 'Russia';

And the requirement is to convert the above to python, thanks in advance!