In odoo 9 (in you have you odoo server in other directory, just change the path to you odoo directory installation)

Create a new custom module:

cd /odoo/odoo-server <--Here inside is the odoo.py script to create a new custom module.

sudo ./odoo.py scaffold myproductviewtreelist /odoo/custom/addons <--This is my directory for my custom modules, this code create a new custom module

cd /odoo/custom/addons/myproductviewtreelist

Edit  __openerp__.py and save this settings:

locate: 'depends': ['base'], and add 'sale' like this:

'depends': ['base','sale'],

Edit emplates.xml and save this settings:

add this code: <--In my case a just want add the default_code field but you can add any field from your product form.

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

<field name="name">my.view.products.tree.inherit</field>

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

<field name="inherit_id" ref="product.product_template_tree_view"/>

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

<!-- Before the field 'name' i add the 'default_code' field, or any field from my product form-->

<field name="name" position="before">

<field name="default_code"/>

</field>

</field>

</record>

Go to top menu/apps on line then go to left menu update apps list, delete the filter in the search box app and put my and search, then install the module myproductviewtreelist

In your __openerp__.py file you should add your custom view:

'data': [
'yourmodule_view.xml'
]

Regards.

In your module you have declared new class custom_products...

and in view you are calling odl class product.product...

rename your module class to :

class product_product (osv.osv):
.....