Additionally, before I tried out the create_db_record...
However whenever I try to commit:
#[§§0§]
student_records = best_node
for rec in student_records.itervalues():
MCS.session.add(rec)
MCS.session.commit()
I get:
sqlalchemy.orm.exc.UnmappedInstanceError: Class
'ProjectParties.Student' is not mapped
What is best_node?
Well it starts from here:
students_preopt = copy.deepcopy(DR.students)
This is passed to a function that spits out something called preopt
(this is where I take one of my best sessions and replicate what the
students dictionary looked like at the time)
And then I pass this to my simulated annealing algorithm which:
best_node = preopt
studOld = best_node
studNew = copy.deepcopy(studOld)
Now if studNew is better that studOld (by some weighting function):
Then best_node = studNew and we find ourselves at #[§§01]
But in short, studNew is the same as students which is mapped to
Student...
I need to get studNew into something that is mapped to
StudentDBRecord... is that where I use the function "create_db_record"
comes in?
On Jun 8, 1:27 am, Az <azfarul.is...@gmail.com> wrote:
> > By default, deepcopy will make one copy of everything in the object
> > graph reachable by the object you feed it. The scary part is that,
> > unless you also pass in a /memo/ argument to each call to deepcopy, it
> > will copy the entire graph /every single call/. So if you deepcopy the
> > students dictionary and then deepcopy the projects dictionary, each
> > student's allocated_proj attribute will not match any instance in the
> > projects dictionary. This is why a use-case-specific copy function is
> > recommended: it is a lot easier to predict which objects will get copied
> > and which objects will be shared.
>
> Shouldn't it match? I mean the student can only get allocated a
> project if it exists in the projects dictionary... or is that not the
> point?
>
> By use-case-specific, you mean I'll have to redefine deepcopy inside
> each class like this: def __deepcopy__(self): something, something?
>
> The only two places where this is an issue is for Supervisor's
> "offered_proj" attribute (a set) where, naturally, each project is an
> object and in Project where "proj_sup" is naturally a supervisor
> object :D
>
> The usefulness of my data structures comes back to bite me now...
>
> > class Student(object):
> > [existing definitions]
>
> > def create_db_record(self):
> > result = StudentDBRecord()
> > result.ee_id = self.ee_id
> > [copy over other attributes]
> > return result
>
> > class StudentDBRecord(object):
> > pass
>
> The create_db_record function... does it have to called explicitly
> somewhere or does it automatically run?
>
> If I now had to commit my Student data to the database... what would I
> do?
>
> > I think a primary key of
> > (run_id, session_id/trial_id, stud_id) would be good
>
> If I make them all primary keys I get a composite key right? Within an
> entire M-C simulation the stud_id's would repeat in groups -- so if
> there are 100 simulations, each stud_id appears 100 times in that
> commit.
>
> Run_id is a fantastic idea! I'd probably have it be the date and time?
> Given that the simulation takes a while to run... the time will have
> changed sufficiently for uniqueness. However, then querying becomes a
> pain because of whatever format the date and time data will be in...
> so in that case, what is a GUID and is that something we could give to
> the Monte-Carlo ourselves before the run as some sort of argument? It
> would be the same for an entire run but different from run to run (so
> not unique from row to row, but unique from one run set to the other).
> Any thoughts on this?
>
> > Never used it, sorry. In general, every UI toolkit has a message/event
> > queue to which you can post messages from any thread. So you could do
> > something like:
>
> > result = monteCarloBasic(...)
>
> > def runs_in_ui_thread():
> > update_database(result)
>
> > ui_toolkit.post_callback(runs_in_ui_thread)
>
> Thanks for that. Now I know what to search for (message, event queue,
> callback) :)
>
> On Jun 7, 10:50 pm, Conor <conor.edward.da...@gmail.com> wrote:
>
> > On 06/07/2010 02:56 PM, Az wrote:
>
> > >> Sounds good. Just beware that deepcopy will try to make copies of all
> > >> the objects referenced by your StudentUnmapped objects (assuming you
> > >> didn't define __deepcopy__), so you may end up copying projects,
> > >> supervisors, etc.
>
> > > Good point. I'm deepcopying my students, projects and supervisors
> > > dictionaries. But yes you're right, all of them have a reference to
> > > other objects.
>
> > > ��[Q1:] How will deepcopying the objects referenced by my
> > > StudentUnmapped object affect me?
>
> > By default, deepcopy will make one copy of everything in the object
> > graph reachable by the object you feed it. The scary part is that,
> > unless you also pass in a /memo/ argument to each call to deepcopy, it
> > will copy the entire graph /every single call/. So if you deepcopy the
> > students dictionary and then deepcopy the projects dictionary, each
> > student's allocated_proj attribute will not match any instance in the
> > projects dictionary. This is why a use-case-specific copy function is
> > recommended: it is a lot easier to predict which objects will get copied
> > and which objects will be shared.
>
> > > I also tried another structure for elegance...
>
> > > class Student(object):
> > > def __init__(self, ee_id, name, stream_id, overall_proby):
> > > self.ee_id = ee_id
> > > self.name = name
> > > self.stream_id = stream_id
> > > self.preferences = collections.defaultdict(set)
> > > self.allocated_project = None
> > > self.allocated_proj_ref = None
> > > self.allocated_rank = None
> > > self.own_project_id = None
> > > self.own_project_sup = None
> > > self.overall_proby = overall_proby
>
> > > def __repr__(self):
> > > return str(self)
>
> > > def __str__(self):
> > > return "%s %s %s: %s (OP: %s)" %(self.ee_id, self.name,
> > > self.allocated_rank, self.allocated_project, self.overall_proby)
>
> > > class StudentDBRecord(Student):
> > > def __init__(self, student):
> > > super(StudentDBRecord, self).__init__(student.ee_id,
> > >
> > > student.name,
> > >
> > > student.stream_id,
> > >
> > > student.preferences,
> > >
> > > student.allocated_project,
> > >
> > > student.allocated_proj_ref,
> > >
> > > student.allocated_rank,
> > >
> > > student.own_project_id,
> > >
> > > student.own_project_sup,
> > >
> > > student.overall_proby)
>
> > > mapper(StudentDBRecord, students_table, properties={'proj_id' :
> > > relation(Project)})
>
> > > Basically, the theory was I'd do all my algorithm stuff on the Student
> > > objects and then after I've found an optimal solution I'll push those
> > > onto the StudentDBRecord table for persistence...
>
> > I don't see any benefit to making StudentDBRecord inherit from Student.
> > Try this:
>
> > class Student(object):
> > [existing definitions]
>
> > def create_db_record(self):
> > result = StudentDBRecord()
> > result.ee_id = self.ee_id
> > [copy over other attributes]
> > return result
>
> > class StudentDBRecord(object):
> > pass
>
> > > However I ended up getting the following error:
>
> > > #####
>
> > > File "Main.py", line 25, in <module>
> > > prefsTableFile = 'Database/prefs-table.txt')
> > > File "/Users/Azfar/Dropbox/Final Year Project/SPAllocation/
> > > DataReader.py", line 158, in readData
> > > readProjectsFile(projectsFile)
> > > File "/Users/Azfar/Dropbox/Final Year Project/SPAllocation/
> > > DataReader.py", line 66, in readProjectsFile
> > > supervisors[ee_id] = Supervisor(ee_id, name, original_quota,
> > > loading_limit)
> > > File "<string>", line 4, in __init__
> > > File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/
> > > lib/python2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/
> > > state.py", line 71, in initialize_instance
> > > fn(self, instance, args, kwargs)
> > > File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/
> > > lib/python2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/
> > > mapper.py", line 1829, in _event_on_init
> > > instrumenting_mapper.compile()
> > > File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/
> > > lib/python2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/
> > > mapper.py", line 687, in compile
> > > mapper._post_configure_properties()
> > > File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/
> > > lib/python2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/
> > > mapper.py", line 716, in _post_configure_properties
> > > prop.init()
> > > File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/
> > > lib/python2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/
> > > interfaces.py", line 408, in init
> > > self.do_init()
> > > File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/
> > > lib/python2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/
> > > properties.py", line 714, in do_init
> > > self._get_target()
> > > File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/
> > > lib/python2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/
> > > properties.py", line 726, in _get_target
> > > self.mapper = mapper.class_mapper(self.argument, compile=False)
> > > File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/
> > > lib/python2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/
> > > util.py", line 564, in class_mapper
> > > raise exc.UnmappedClassError(class_)
> > > sqlalchemy.orm.exc.UnmappedClassError: Class 'ProjectParties.Student'
> > > is not mapped
>
> > > #####
>
> > > ��[Q2:] What's that all about? Something wrong with the inheritence?
>
> > I don't know if there is a way to get the
>
> ...
>
> read more »
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