How can I use contains and iexact Field lookups at the same query in Django?

Like that ..

casas = Casa.objects.filter(nome_fantasia__contains__iexact="green")

If you need case-insensitive contains, use icontains:

casas = Casa.objects.filter(nome_fantasia__icontains="green")

Which is converted to

... WHERE nome_fantasia ILIKE '%green%'

in SQL.

Honestly, you don’t need to. The two resultsets overlap. If you were intending AND then just use the most restrictive: __iexact. if you want OR use __contains

Just to answer your question you could do something like below (note this is an AND)

casas = Casa.objects.filter(nome_fantasia__contains="green", nome_fantasia__iexact="green")