阅读

Read Inserts, Updates and Deletes section of the documentation. Following code should get you started:

from sqlalchemy.sql.expression import bindparam
stmt = addresses.update().\
    where(addresses.c.id == bindparam('_id')).\
    values({
        'user_id': bindparam('user_id'),
        'email_address': bindparam('email_address'),
    })

conn.execute(stmt, [
    {'user_id': 1, 'email_address' : 'jack@yahoo.com', '_id':1},
    {'user_id': 1, 'email_address' : 'jack@msn.com', '_id':2},
    {'user_id': 2, 'email_address' : 'www@www.org', '_id':3},
    {'user_id': 2, 'email_address' : 'wendy@aol.com', '_id':4},
])