make default value sqlalchemy orm code example

Example 1: sqlalchemy function for default value for column

def mydefault(context):
    return context.get_current_parameters()['counter'] + 12

t = Table('mytable', meta,
    Column('counter', Integer),
    Column('counter_plus_twelve', Integer, default=mydefault, onupdate=mydefault)
)

Example 2: sqlalchemy default value for column

Table("mytable", meta,
    Column("somecolumn", Integer, default=12)
)