psql.txt

jon=# \d foo
                                Table "public.foo"
 Column |         Type          |                    Modifiers                     
--------+-----------------------+--------------------------------------------------
 id     | integer               | not null default nextval('foo_id_seq'::regclass)
 key    | character varying(20) | not null
 value  | character varying     | not null
Indexes:
    "foo_pkey" PRIMARY KEY, btree (id)
    "foo_key_key" UNIQUE CONSTRAINT, btree (key)

jon=# \d bar
                                Table "public.bar"
 Column |         Type          |                    Modifiers                     
--------+-----------------------+--------------------------------------------------
 id     | integer               | not null default nextval('bar_id_seq'::regclass)
 key    | character varying(20) | not null
 value  | character varying     | not null
Indexes:
    "bar_pkey" PRIMARY KEY, btree (id)
    "bar_key_key" UNIQUE CONSTRAINT, btree (key)

sample.py

from sqlalchemy import create_engine, MetaData, Table, Column, Integer, Unicode
from sqlalchemy.dialects.postgresql import INTEGER

meta = MetaData()
foo = Table('foo', meta,
            Column('id', Integer, primary_key=True),
            Column('key', Unicode(20), unique=True, nullable=False),
            Column('value', Unicode, nullable=False))

bar = Table('bar', meta,
            Column('id', INTEGER, primary_key=True),
            Column('key', Unicode(20), unique=True, nullable=False),
            Column('value', Unicode, nullable=False))


engine = create_engine("postgres://jon@127.0.0.1/jon")

meta.create_all(bind=engine)