django error: __init__() takes exactly 1 argument (2 given) - django

Question

I've written a sqlalchemy model called 'library':
class Library(Base):
__tablename__ = 'library'
id = Column(Integer, primary_key=True)
details = Column(String)
def __init__(self, details):
self.details = details
def __repr__(self):
return u"Library(%s)" % (self.details)
Then, inside the views.py file, I've written:
def is_lib_empty():
return len(session.query(Library).all()) <= 0
def populateLib():
new_libs = [Library('one'), Library('two'), Library('three'), Library('four')]
session.add_all(new_libs)
session.commit()
def index(request):
if is_lib_empty():
populateLib()
libs = session.query(Library).all()
return render_to_response('../templates/index.html',{'libs':libs})
And then I run python manage.py runserver, and it shows me an error message:
__init__() takes exactly 1 argument (2 given)
What should I do to fix this?
TypeError at /
__init__() takes exactly 1 argument (2 given)
Request Method: GET
Django Version: 1.3.1
Exception Type: TypeError
Exception Value:
__init__() takes exactly 1 argument (2 given)
Exception Location: /cs/wetlab/Limor/workspace/Yeasti/Yeasti/loose_coupling/../loose_coupling/with_sqlalchemy/views.py in populateLib, line 25
Python Executable: /sw/bin/python2.7
Python Version: 2.7.2
Python Path:
['/cs/wetlab/Limor/workspace/Yeasti/Yeasti/loose_coupling',
'/sw/lib/python27.zip',
'/sw/lib/python2.7',
'/sw/lib/python2.7/plat-darwin',
'/sw/lib/python2.7/plat-mac',
'/sw/lib/python2.7/plat-mac/lib-scriptpackages',
'/sw/lib/python2.7/lib-tk',
'/sw/lib/python2.7/lib-old',
'/sw/lib/python2.7/lib-dynload',
'/sw/lib/python2.7/site-packages',
'/sw/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg-info']
Server time: Sun, 1 Jul 2012 05:50:03 -0500
Environment:
Request Method: GET
Django Version: 1.3.1
Python Version: 2.7.2
Installed Applications:
['loose_coupling.with_sqlalchemy']
Installed Middleware:
('django.middleware.common.CommonMiddleware',)
Traceback:
File "/sw/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
111. response = callback(request, *callback_args, **callback_kwargs)
File "/cs/wetlab/Limor/workspace/Yeasti/Yeasti/loose_coupling/../loose_coupling/with_sqlalchemy/views.py" in index
39. populateLib()
File "/cs/wetlab/Limor/workspace/Yeasti/Yeasti/loose_coupling/../loose_coupling/with_sqlalchemy/views.py" in populateLib
25. new_libs = [Library('one'), Library('two'), Library('three'), Library('four')]
Exception Type: TypeError at /
Exception Value: __init__() takes exactly 1 argument (2 given)

Answer 1

UPDATE:
You can always use the default constructor, using keyword arguments:
Library(details='some details')
as described in http://docs.sqlalchemy.org/en/rel_0_7/orm/tutorial.html
This is supported by the default constructor, no need to override it. Anyway, your code should work, unless there is some override somewhere...