ValueError: Wrong value for inward.item_category: {u'time_in': False, u'vehicle_type': False, u'lc': False, u'vehicle': False, u'invoice_ref': False, u'bilty': False, u'date': False, u'gin': False, u'time_out': False, u'document_type': False, u'id': False, u'supplier_details': False}

.py file

class inwardpass(models.Model):

_name='inwardpass'

date = fields.Date('Date', required=True)

document_type = fields.Boolean('LC or PO')

invoice_ref = fields.Char('Invoice Ref #')

gin = fields.Char('GIN #')

lc = fields.Char('LC Ref.#/PO #')

bilty = fields.Char('Bilty ')

time_out = fields.Date('Time Out', required=True)

vehicle = fields.Char('Vehicle')

time_in = fields.Date('Time In', required=True)

vehicle_type = fields.Char('Vehicle Type')

supplier_details= fields.Char('Supplier Details')

Details = fields.One2many('inward','item_category',ondelete='cascade')

class inward(models.Model):

_name = 'inward'

item_category = fields.One2many('inwardpass','Details','Item Category')

uom = fields.Char('UOM')

qty = fields.Char('QTY')

item = fields.Char('Item Category')

XML file

<notebook position="after">

<page string="Details">

<group col="4" colspan="4" string="General">

<field name="Details"  >

<tree>

<field name="item" placeholder="Item Category" />

<field name="uom" placeholder="UMO"/>

<field name="qty" placeholder="Quantity"/>

</tree>

</field>

</group>

</page>

</notebook>