create field, view_form, view_tree 'cliente_type'

__init__.py

@@ -1,8 +1,9 @@
 from trytond.pool import Pool
-from . import product, sale, purchase, equipment
+from . import party, product, purchase, sale, equipment
 
 def register():
     Pool.register(
+        party.Party,
         product.Template,
         product.Product,
         purchase.Purchase,

party.py

@@ -0,0 +1,10 @@
+from trytond.pool import PoolMeta
+from trytond.model import ModelSQL, ModelView, fields
+
+_CLIENT_TYPE = [('ips', 'IPS'),
+                ('optica', 'Optica')]
+
+class Party(metaclass=PoolMeta):
+    __name__ = 'party.party'
+
+    client_type = fields.Selection(_CLIENT_TYPE, 'Client type')

tryton.cfg

@@ -10,7 +10,9 @@ depends:
     stock
     country
 xml:
+    party.xml
     product.xml
     equipment.xml
     sale.xml
-    purchase.xml
+    purchase.xml
+