Next / Previous / Contents / NM Tech homepage

6.8. The circles table

This table's name will be circles_table. For attributes, see Section 4.1.3, “Attributes of the circles table”.
    circles_table = schema.Table('circles', meta,
        schema.Column('lat',       types.CHAR(4)),
        schema.Column('lon',       types.CHAR(5)),
        schema.Column('water',     types.CHAR(1)),
        schema.Column('odd',       types.CHAR(1)),
        schema.Column('cir_name',  types.VARCHAR(80), nullable=False),
        schema.PrimaryKeyConstraint('lat', 'lon'))

Instances of class Circle will represent these rows in SQLAlchemy.
    class Circle(object):
        def __init__(self, lat, lon, water, odd, cir_name):
   = lat
            self.lon = lon
            self.water = water
            self.odd = odd
            self.cir_name = cir_name
        def __repr__(self):
            return ( "<Circle(%sn %sw %s)>" %
                     (, self.lon, self.cir_name) )
        def __cmp__(self, other):
            return cmp(self.cir_name, other.cir_name)

The .fullName() function returns a string representation with the region codes filled in. Note that the region codes are available only through the .regions attribute that is added in Section 6.13, “Object-relational mapping”. Just the region part is available as .allRegions(), and a Unicode rendering of the full name, with degree and prime symbols, is available as .unicode().
        def allRegions(self):
            return '-'.join ( [ reg.reg_code
                                for reg in self.regions ] )
        def fullName(self):
            return ( "%sn %sw %s: %s" %
                     (, self.lon, self.allRegions(),
                      self.cir_name) )
        def unicode(self):
            return ( u"%s%s%s%sN %s%s%s%sW %s: %s" %
                     ([:2], DEGREE,[2:], PRIME,
                      self.lon[:3], DEGREE, self.lon[3:], PRIME,
                      self.allRegions(), self.cir_name) )