I like to add some fields in the warehouse so I added the class with columns in the stock.py. But it shows error. I can not find what the error is.

The error message is

Traceback (most recent call last):
File "/home/rck/Desktop/odoo-8.0/openerp/http.py", line 539, in _handle_exception return super(JsonRequest, self)._handle_exception(exception) File "/home/rck/Desktop/odoo-8.0/openerp/http.py", line 590, in dispatch return self._json_response(result) File "/home/rck/Desktop/odoo-8.0/openerp/http.py", line 528, in _json_response body = simplejson.dumps(response) File "/usr/local/lib/python2.7/dist-packages/simplejson/__init__.py", line 366, in dumps return _default_encoder.encode(obj) File "/usr/local/lib/python2.7/dist-packages/simplejson/encoder.py", line 269, in encode chunks = self.iterencode(o, _one_shot=True) File "/usr/local/lib/python2.7/dist-packages/simplejson/encoder.py", line 348, in iterencode return _iterencode(o, 0) File "/usr/local/lib/python2.7/dist-packages/simplejson/encoder.py", line 246, in default

raise TypeError(repr(o) + " is not JSON serializable")

TypeError: product.step1() is not JSON serializable


My py code in stock.py is

class product_step1(osv.osv):
_name = "product.step1"

_columns = {

'name':fields.float('Name'),

'b':fields.float('B'),

'c':fields.float('C'),

'd':fields.float('D'),

'e':fields.float('E'),

'f':fields.float('F'),

'g':fields.float('G'),

'h':fields.float('H'),

'i':fields.float('I'),

'j':fields.float('J'),

}

my xml code in stock_view.xml is


<record model="ir.ui.view" id="step1_tree_view">

<field name="name">step1.tree</field>

<field name="model">product.step1</field>

<field name="type">tree</field>

<field name="arch" type="xml">

<tree string="Product Details">

<field name="name"/>

<field name="b"/>

<field name="c"/>

</tree> </field> </record>


<record model="ir.ui.view" id="step1_form_view">

<field name="name">step1.form</field>

<field name="model">product.step1</field>

<field name="type">form</field>

<field name="arch" type="xml">

<form string="Product Details">

<sheet>

<group>

<group>

<field name="name"/>

<field name="b"/>

<field name="c"/>

<field name="d"/>

<field name="e"/>

</group>

<group>

<field name="f"/>

<field name="g"/>

<field name="h"/>

<field name="i"/>

<field name="j"/>

</group>

</group>

</sheet>

</form> </field> </record>


<record model="ir.actions.act_window" id="action_step1_form">

<field name="name">step1</field>

<field name="res_model">product.step1</field>

</record>
<menuitem name="Product Details" parent="menu_stock_root" id="step1_menu_mainform"/>

<menuitem name="Product Description" parent="step1_menu_mainform" id="step1_menu1_mainform" action="action_step1_form"/>


When I click the Quants and stock Moves tab in warehouse this error has been shown.

Notify me where I'm doing the mistake.

Thank you.