Attributeerror: 'nonetype' Object Has No Attribute '_columns'

I am writing a module in OpenERP that would inherit from the Accounts module. Below is my simplified code from osv import fields, osv import decimal_precision as dp class account_

Solution 1:

Please check the dependency of the module you have created. In the openerp.py file, in the dependency list if 'account' is not added, please add it. If this didnt solve your problem please provide the error log

Solution 2:

does this solve the problem?

class account_molly(osv):
    ... 

you seem to mix module and class and class attribute