It’s possible to create a mixin for a table that overrides something, however unless it itself is a subclass of Table class variable instances of Column will not be added to the class which is using the mixin.
Example:
>>> class UselessMixin(object):
... extra = tables.Column()
...
>>> class TestTable(UselessMixin, tables.Table):
... name = tables.Column()
...
>>> TestTable.base_columns.keys()
['name']
To have a mixin contribute a column, it needs to be a subclass of Table. With this in mind the previous example should have been written as follows:
>>> class UsefulMixin(tables.Table):
... extra = tables.Column()
...
>>> class TestTable(UsefulMixin, tables.Table):
... name = tables.Column()
...
>>> TestTable.base_columns.keys()
['extra', 'name']