Odoo If statement with category - odoo

Question

Hi I am using Odoo10 and I have some products assigned to categorys. On my Sale Order screen I have 2 selection boxes one is Carpet and the other is Flooring. Below is my code for showing cetain fields
#api.onchange('squarebox')
def _onchange_default_code(self):
if self.flooring2:
self.boxes = (self.squaremtr) / (self.squarebox or 1)
self.squaremtrsold = (self.squarebox or 1) * (self.suggestbox)
Instead of using a selection field I was wondering if it is possible to do an IF statement based on Category the product is in. So instead of if self.flooring2:something like
if self.productid is in category Carpet:

Answer 1

First add this two category in Category Master then select this Internal category in Product you want.
Your XML File :
<record id="category_flooring" model="product.category">
<field name="name">Flooring</field>
<field name="type">normal</field>
<field name="property_cost_method">standard</field>
<field name="property_valuation">manual_periodic</field>
</record>
<record id="category_carpet" model="product.category">
<field name="name">Carpet</field>
<field name="type">normal</field>
<field name="property_cost_method">standard</field>
<field name="property_valuation">manual_periodic</field>
</record>
Now your python code goes like this:-
#api.onchange('product_id')
def _onchange_default_code(self):
if self.product_id.categ_id.id == self.env.ref('your_module_name.category_flooring').id:
# Your code belongs to flooring category
elif self.product_id.categ_id.id == self.env.ref('your_module_name.category_carpet').id:
# Your code belongs to carpet category

Answer 2

If I understand correctly, you want to show or hide some fields depending on values from other fields of the same record.
To do so use the invisible attribute on the form view definition, not a python function. I would use a python function decorated with an #api.onchange to calculate other values that depend on squarebox.
See for example addons/sale/views/sale_views.xml around line 227:
<field name="validity_date" attrs="{'invisible': [('state', 'in', ['sale', 'done'])]}"/>
The line above translates to plain English as: Show the validity_date field except when the state field is either sale or done.