- modernizing examples

1 files changed, 47 insertions, 31 deletions

diff --git a/examples/inheritance/polymorph.py b/examples/inheritance/polymorph.py
index 7ca207f9f..872318060 100644
--- a/examples/inheritance/polymorph.py
+++ b/examples/inheritance/polymorph.py
@@ -1,19 +1,20 @@
-from sqlalchemy import MetaData, Table, Column, Integer, String, ForeignKey
-from sqlalchemy.orm import mapper, relationship, create_session
-import sets
+from sqlalchemy import MetaData, Table, Column, Integer, String, \
+    ForeignKey, create_engine
+from sqlalchemy.orm import mapper, relationship, sessionmaker
+
 
 # this example illustrates a polymorphic load of two classes
 
-metadata = MetaData('sqlite://')
-metadata.bind.echo = True
+metadata = MetaData()
 
 # a table to store companies
 companies = Table('companies', metadata, 
    Column('company_id', Integer, primary_key=True),
    Column('name', String(50)))
 
-# we will define an inheritance relationship between the table "people" and "engineers",
-# and a second inheritance relationship between the table "people" and "managers"
+# we will define an inheritance relationship between the table "people" and
+# "engineers", and a second inheritance relationship between the table
+# "people" and "managers"
 people = Table('people', metadata, 
    Column('person_id', Integer, primary_key=True),
    Column('company_id', Integer, ForeignKey('companies.company_id')),
@@ -21,20 +22,20 @@ people = Table('people', metadata,
    Column('type', String(30)))
    
 engineers = Table('engineers', metadata, 
-   Column('person_id', Integer, ForeignKey('people.person_id'), primary_key=True),
+   Column('person_id', Integer, ForeignKey('people.person_id'), 
+                                    primary_key=True),
    Column('status', String(30)),
    Column('engineer_name', String(50)),
    Column('primary_language', String(50)),
   )
    
 managers = Table('managers', metadata, 
-   Column('person_id', Integer, ForeignKey('people.person_id'), primary_key=True),
+   Column('person_id', Integer, ForeignKey('people.person_id'), 
+                                    primary_key=True),
    Column('status', String(30)),
    Column('manager_name', String(50))
    )
    
-metadata.create_all()
-
 # create our classes.  The Engineer and Manager classes extend from Person.
 class Person(object):
     def __init__(self, **kwargs):
@@ -44,10 +45,14 @@ class Person(object):
         return "Ordinary person %s" % self.name
 class Engineer(Person):
     def __repr__(self):
-        return "Engineer %s, status %s, engineer_name %s, primary_language %s" % (self.name, self.status, self.engineer_name, self.primary_language)
+        return "Engineer %s, status %s, engineer_name %s, "\
+                "primary_language %s" % \
+                    (self.name, self.status, 
+                        self.engineer_name, self.primary_language)
 class Manager(Person):
     def __repr__(self):
-        return "Manager %s, status %s, manager_name %s" % (self.name, self.status, self.manager_name)
+        return "Manager %s, status %s, manager_name %s" % \
+                    (self.name, self.status, self.manager_name)
 class Company(object):
     def __init__(self, **kwargs):
         for key, value in kwargs.iteritems():
@@ -56,30 +61,43 @@ class Company(object):
         return "Company %s" % self.name
 
 
-person_mapper = mapper(Person, people, polymorphic_on=people.c.type, polymorphic_identity='person')
-mapper(Engineer, engineers, inherits=person_mapper, polymorphic_identity='engineer')
-mapper(Manager, managers, inherits=person_mapper, polymorphic_identity='manager')
+person_mapper = mapper(Person, people, polymorphic_on=people.c.type,
+                       polymorphic_identity='person')
+mapper(Engineer, engineers, inherits=person_mapper,
+       polymorphic_identity='engineer')
+mapper(Manager, managers, inherits=person_mapper,
+       polymorphic_identity='manager')
+
+mapper(Company, companies, properties={'employees'
+       : relationship(Person, lazy='joined', backref='company',
+       cascade='all, delete-orphan')})
+
+engine = create_engine('sqlite://', echo=True)
+
+metadata.create_all(engine)
 
-mapper(Company, companies, properties={
-    'employees': relationship(Person, lazy='joined', backref='company', cascade="all, delete-orphan")
-})
+session = sessionmaker(engine)()
 
-session = create_session()
 c = Company(name='company1')
-c.employees.append(Manager(name='pointy haired boss', status='AAB', manager_name='manager1'))
-c.employees.append(Engineer(name='dilbert', status='BBA', engineer_name='engineer1', primary_language='java'))
+c.employees.append(Manager(name='pointy haired boss', status='AAB',
+                   manager_name='manager1'))
+c.employees.append(Engineer(name='dilbert', status='BBA',
+                   engineer_name='engineer1', primary_language='java'))
 c.employees.append(Person(name='joesmith', status='HHH'))
-c.employees.append(Engineer(name='wally', status='CGG', engineer_name='engineer2', primary_language='python'))
-c.employees.append(Manager(name='jsmith', status='ABA', manager_name='manager2'))
+c.employees.append(Engineer(name='wally', status='CGG',
+                   engineer_name='engineer2', primary_language='python'
+                   ))
+c.employees.append(Manager(name='jsmith', status='ABA',
+                   manager_name='manager2'))
 session.add(c)
 
-session.flush()
-session.expunge_all()
+session.commit()
 
 c = session.query(Company).get(1)
 for e in c.employees:
     print e, e._sa_instance_state.key, e.company
-assert sets.Set([e.name for e in c.employees]) == sets.Set(['pointy haired boss', 'dilbert', 'joesmith', 'wally', 'jsmith'])
+assert set([e.name for e in c.employees]) == set(['pointy haired boss',
+        'dilbert', 'joesmith', 'wally', 'jsmith'])
 print "\n"
 
 dilbert = session.query(Person).filter_by(name='dilbert').one()
@@ -88,14 +106,12 @@ assert dilbert is dilbert2
 
 dilbert.engineer_name = 'hes dibert!'
 
-session.flush()
-session.expunge_all()
+session.commit()
 
 c = session.query(Company).get(1)
 for e in c.employees:
     print e
 
 session.delete(c)
-session.flush()
+session.commit()
 
-metadata.drop_all()