Question

I have a webscraper that delivers dictionary objects of data to be entered into the Django model. I’ve written a simple script to test loading data. It operates by iterating through the dictionary object and delivering each key value into the appropriate model field (the keys share their names with the respective model fields). While my new model object accepts the data, it isn’t retained after the iteration. I can’t figure out why.

In [1]: from events.models import Event

In [2]: eventObject = Event() #New model object to hold the item.

In [3]: item = {'title': 'hellooo', 'description': 'just a test', 'eventid': '412212'} #We want to load this item into the eventObject

In [4]: for k in item.keys():
...:     eventObject.k = item[k]
...:     print "eventObject.%s: " % (k) + eventObject.k

eventObject.eventid: 412212 #eventObject received the item's data, as to be expected...
eventObject.description: just a test
eventObject.title: hellooo

In [5]: eventObject #but now eventObject is still empty!
Out[5]: <Event: >

In [6]: eventObject.title #just making sure.
Out[6]: ''

In [7]: for k in item.keys():
    eventObject.k = item[k]
    print "eventObject.%s: " % (k) + eventObject.k
    eventObject.save()  #Oh, maybe we need to save it...

eventObject.eventid: 412212
---------------------------------------------------------------------------
IntegrityError                            Traceback (most recent call last)

/home/anthony/Dropbox/Projects/Django/livingCityMap/<ipython console> in <module>()

/usr/local/lib/python2.7/dist-packages/django/db/models/base.pyc in save(self, force_insert, force_update, using)
    458         if force_insert and force_update:
    459             raise ValueError("Cannot force both insert and updating in model saving.")
--> 460         self.save_base(using=using, force_insert=force_insert, force_update=force_update)
    461 
    462     save.alters_data = True

/usr/local/lib/python2.7/dist-packages/django/db/models/base.pyc in save_base(self, raw, cls, origin, force_insert, force_update, using)
    551                 if values:
    552                     # Create a new record.

--> 553                     result = manager._insert(values, return_id=update_pk, using=using)
    554                 else:
    555                     # Create a new record with defaults for everything.


/usr/local/lib/python2.7/dist-packages/django/db/models/manager.pyc in _insert(self, values, **kwargs)
    193 
    194     def _insert(self, values, **kwargs):
--> 195         return insert_query(self.model, values, **kwargs)
    196 
    197     def _update(self, values, **kwargs):

/usr/local/lib/python2.7/dist-packages/django/db/models/query.pyc in insert_query(model, values, return_id, raw_values, using)
1432     part of the public API.
1433     """
1434     query = sql.InsertQuery(model)
1435     query.insert_values(values, raw_values)
-> 1436     return query.get_compiler(using=using).execute_sql(return_id)

/usr/local/lib/python2.7/dist-packages/django/db/models/sql/compiler.pyc in execute_sql(self, return_id)
    789     def execute_sql(self, return_id=False):
    790         self.return_id = return_id
--> 791         cursor = super(SQLInsertCompiler, self).execute_sql(None)
    792         if not (return_id and cursor):
    793             return

/usr/local/lib/python2.7/dist-packages/django/db/models/sql/compiler.pyc in execute_sql(self, result_type)
    733 
    734         cursor = self.connection.cursor()
--> 735         cursor.execute(sql, params)
    736 
    737         if not result_type:

/usr/local/lib/python2.7/dist-packages/django/db/backends/util.pyc in execute(self, sql, params)
    32         start = time()
    33         try:
---> 34             return self.cursor.execute(sql, params)
    35         finally:
    36             stop = time()

/usr/local/lib/python2.7/dist-packages/django/db/backends/postgresql_psycopg2/base.pyc in execute(self, query, args)
    42     def execute(self, query, args=None):
    43         try:
---> 44             return self.cursor.execute(query, args)
    45         except Database.IntegrityError, e:
    46             raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]

IntegrityError: null value in column "eventid" violates not-null constraint

And the model, just in case you’re curious:
from django.contrib.gis.db import models

class Event(models.Model):
    title = models.CharField(max_length=200)
    description = models.TextField()
    eventid = models.IntegerField(max_length=200)
    genre = models.CharField(max_length=200)
    contact = models.CharField(max_length=200)
    cost = models.CharField(max_length=200)

    venue = models.CharField(max_length=200)
    address = models.CharField(max_length=200)
    neighborhood = models.CharField(max_length=200)
    city = models.CharField(max_length=200)


    date = models.DateTimeField()  # This will be replaced by a new class
    time = models.CharField(max_length=200) # This should obviously be datetime and probably exist in it's own class, but first requires the input to be normalized (via serious RegEx magic)
    def __unicode__(self):
        return self.title

Answer 1

You can not set an attribute by a variable value in that way. eventOjbect.k = 'hello' is just setting an attribute, k to 'hello' which the model doesn’t have.

You are simply assigning eventObject.k = ‘foo’ and repeating that over and over.

for k in item.keys():
    setattr(eventObject, k, item[k])
    print "eventObject.%s: " % (k) + eventObject.k

Or in your case you could just pass those key/value pairs into the model constructor

eventObject = Event(**items)