The pprintout was:
{<type 'collections.defaultdict'>: 156,
<type 'bool'>: 2,
<type 'float'>: 1,
<type 'int'>: 538,
<type 'list'>: 1130,
<type 'dict'>: 867,
<type 'NoneType'>: 1,
<type 'set'>: 932,
<type 'str'>: 577,
<type 'tuple'>: 1717,
<type 'type'>: 5,
<class 'sqlalchemy.util.symbol'>: 1,
<class 'sqlalchemy.orm.state.InstanceState'>: 236,
<class 'ProjectParties.Student'>: 156,
<class 'ProjectParties.Supervisor'>: 39,
<class 'ProjectParties.Project'>: 197}
I think the InstanceStates come from the Supervisor and Project
classes (197+39 = 236)
> Sounds pretty ugly. What if you add extra tables to represent runs
> and/or trials?
>
> class Run(Base):
> # Having a separate table here gives you nice auto-incrementing run ids
> # and lets you attach additional information to a run, such as timestamp,
> # human-supplied comment, etc.
> __tablename__ = 'run'
> id = Column(Integer, primary_key=True)
> timestamp = Column(DateTime, nullable=False)
> # comment = Column(UnicodeText(100), nullable=False)
>
> trials = relationship('Trial',
> back_populates='run',
> order_by=lambda: Trial.id.asc())
>
> class Trial(Base):
> # Having a separate table here is of dubious value, but hey it makes the
> # relationships a bit nicer!
> __tablename__ = 'trial'
> __table_args__ = (PrimaryKeyConstraint('run_id', 'id'), {})
> run_id = Column(Integer, ForeignKey('run.id'))
> id = Column(Integer)
>
> run = relationship('Run', back_populates='trials')
> sim_allocs = relationship('SimAllocation', back_populates='trial')
>
> class SimAllocation(Base):
> ...
> __table_args__ = (PrimaryKeyConstraint('run_id', 'trial_id', 'stud_id'),
> ForeignKeyConstraint(['run_id', 'trial_id'],
> ['trial.run_id', 'trial.id']),
> {})
>
> run_id = Column(Integer)
> trial_id = Column(Integer)
> stud_id = Column(Integer)
>
> trial = relationship('Trial', back_populates='sim_allocs')
Ah true, my solution was rather hacky and not very elegant.
Your class definitions... are you defining both table and Class in one
go? Would I have to change the way my monteCarloBasic creates
instances of SimAllocation?
On Jun 9, 9:46 pm, Conor <[email protected]> wrote:
> On 06/09/2010 02:45 PM, Az wrote:
>
>
>
> >> Expected: students, supervisors, projects, dictionaries of said objects,
> >> and other attribute values (strings, ints, lists, etc.). Unexpected:
> >> anything else, especially sessions, InstanceState objects, or other ORM
> >> support objects.
>
> > Actually got some stuff like the following (copy-pasting bits from my
> > print output):
>
> > (<class 'sqlalchemy.orm.state.InstanceState'>,)
> > {'_sa_instance_state': <sqlalchemy.orm.state.InstanceState object at
> > 0x2d5beb0>, 'proj_id': 1100034, 'postsim_probs': [], 'proj_sup': 1291,
> > 'presim_pop': 0, 'own_project': False, 'allocated': False,
> > 'proj_name': 'MPC on a Chip', 'blocked': False}
>
> > Stuff like that :S
>
> I'm not sure what that printout indicates. Try this as your debug printout:
>
> def get_memo_type_count(memo):
> retval = {}
> for obj in memo.itervalues():
> type_ = obj.__class__
> retval[type_] = retval.get(type_, 0) + 1
> return retval
>
> [perform deep copies]
> type_count = get_memo_type_count(memo)
> import pprint
> pprint.pprint(type_count)
>
> This will tell you, e.g. how may Student objects were copied, how many
> InstanceState objects were copied, etc. Remember that you will have to
> override __deepcopy__ on your mapped classes or use the
> use-case-specific copy function to prevent ORM attributes (such as
> _sa_instance_state) from being copied.
>
>
>
> > [...]
> >> The most likely cause is if you call session.add(temp_alloc) after
> >> calling session.merge(temp_alloc) for the same temp_alloc object. I
> >> noticed your original monteCarloBasic had two calls to
> >> session.add(temp_alloc); did both get changed to
> >> session.merge(temp_alloc)? If that doesn't work, can you verify that
> >> SQLAlchemy's primary key for SimAllocation matches the database's
> >> primary key for sim_alloc? What column type are you using for uid? Which
> >> call to session.merge is failing (line 163 according to your traceback),
> >> the one inside your "for rank in ranks" loop or the one outside?
>
> > Oh yeah good point, they're separate calls. Basically for the one in
> > "for rank in ranks"
> > adds for a student getting a project, the other adds if a student
> > doesn't get a project since we want
> > to track all students (allocated or not, since the state of being
> > unallocated is what gives
> > us motivation to optimise the results).
>
> Your original monteCarloBasic definition had this:
>
> for rank in ranks:
> proj = random.choice(list(student.preferences[rank]))
> if not (proj.allocated or proj.blocked or proj.own_project):
> [...]
> session.add(temp_alloc) # #1
> break
>
> ident += 1
> session.add(temp_alloc) # #2
>
> session.add #1 is redundant since #2 gets called regardless of whether
> the student gets allocated a project or not (ignoring exceptions). Just
> a minor nitpick.
>
> > Anyway, session.merge() is for overwriting previously existing values
> > right? Now thanks to the UUID I can add multiple calls to
> > monteCarloBasic() to my physical database :)
>
> session.merge gives you "find or create" behavior: look for an existing
> object in the database, or create a new one if no existing object is
> found. Note that session.merge requires you to completely fill in the
> object's primary key whereas session.add does not.
>
> > I basically wrote a small function that, for everytime the
> > monteCarloBasic() is called, will append the UUID, the number of
> > trials ran and the date-time to a text file. My supervisor would have
> > to copy paste that into a GUI text field or the command line but it's
> > not that much of a hassle, given the usefulness of the database.
>
> Sounds pretty ugly. What if you add extra tables to represent runs
> and/or trials?
>
> class Run(Base):
> # Having a separate table here gives you nice auto-incrementing run ids
> # and lets you attach additional information to a run, such as timestamp,
> # human-supplied comment, etc.
> __tablename__ = 'run'
> id = Column(Integer, primary_key=True)
> timestamp = Column(DateTime, nullable=False)
> # comment = Column(UnicodeText(100), nullable=False)
>
> trials = relationship('Trial',
> back_populates='run',
> order_by=lambda: Trial.id.asc())
>
> class Trial(Base):
> # Having a separate table here is of dubious value, but hey it makes the
> # relationships a bit nicer!
> __tablename__ = 'trial'
> __table_args__ = (PrimaryKeyConstraint('run_id', 'id'), {})
> run_id = Column(Integer, ForeignKey('run.id'))
> id = Column(Integer)
>
> run = relationship('Run', back_populates='trials')
> sim_allocs = relationship('SimAllocation', back_populates='trial')
>
> class SimAllocation(Base):
> ...
> __table_args__ = (PrimaryKeyConstraint('run_id', 'trial_id', 'stud_id'),
> ForeignKeyConstraint(['run_id', 'trial_id'],
> ['trial.run_id', 'trial.id']),
> {})
>
> run_id = Column(Integer)
> trial_id = Column(Integer)
> stud_id = Column(Integer)
>
> trial = relationship('Trial', back_populates='sim_allocs')
>
> -Conor
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