self.base_columns not emptied on init

[fkdeboer]

Hi, I add some extra columns dynamically through the init (see code below), which works for me. However, when changing view and coming back, at first the columns are still there, while extra_columns is empty, so no the columns are not added.
This is caused by self.base_columns not being empty at init. Is this intended, or a bug/feature in tables2?
Or is this because of my code, and is there a neater/better way to add columns dynamically?
feedback welcome.

class FooTable(Table):
    Foo=Column()

    def __init__(self, *args, **kwargs):
        extra_columns = kwargs.pop('extra_columns', [])
        for column_name in extra_columns:
               self.base_columns[column_name] = Column()
        super(FooTable, self).__init__(*args, **kwargs)

[intiocean]

This is the same issue as discussed in #70

[fkdeboer]

indeed!
sorry to have missed that.