[FIX] undefined variables (potential nameerror)

Backport 9ec0455abc and
6a601fe6dc as they fixed various
possible NameError but did so in later sub-releases.

addons/account/tests/test_reconciliation.py

@@ -1,3 +1,4 @@
+from odoo import api
 from odoo.addons.account.tests.account_test_classes import AccountingTestCase
 import time
 import unittest

addons/base_sparse_field/models/models.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
-from odoo import models, fields, api
+from odoo import models, fields, api, _
+from odoo.exceptions import UserError
 
 
 class IrModelFields(models.Model):

addons/mail/models/mail_channel.py

@@ -4,7 +4,7 @@ import base64
 from email.utils import formataddr
 
 import re
-import uuid
+from uuid import uuid4
 
 from odoo import _, api, fields, models, modules, tools
 from odoo.exceptions import UserError
@@ -56,7 +56,7 @@ class Channel(models.Model):
         ('channel', 'Channel')],
         'Channel Type', default='channel')
     description = fields.Text('Description')
-    uuid = fields.Char('UUID', size=50, index=True, default=lambda self: '%s' % uuid.uuid4(), copy=False)
+    uuid = fields.Char('UUID', size=50, index=True, default=lambda self: str(uuid4()), copy=False)
     email_send = fields.Boolean('Send messages by email', default=False)
     # multi users channel
     channel_last_seen_partner_ids = fields.One2many('mail.channel.partner', 'channel_id', string='Last Seen')

addons/point_of_sale/models/pos_config.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
-import uuid
+from uuid import uuid4
 
 from odoo import api, fields, models, _
 from odoo.exceptions import ValidationError
@@ -110,7 +110,7 @@ class PosConfig(models.Model):
     proxy_ip = fields.Char(string='IP Address', size=45,
         help='The hostname or ip address of the hardware proxy, Will be autodetected if left empty.')
     active = fields.Boolean(default=True)
-    uuid = fields.Char(readonly=True, default=lambda self: str(uuid.uuid4()),
+    uuid = fields.Char(readonly=True, default=lambda self: str(uuid4()),
         help='A globally unique identifier for this pos configuration, used to prevent conflicts in client-generated data.')
     sequence_id = fields.Many2one('ir.sequence', string='Order IDs Sequence', readonly=True,
         help="This sequence is automatically created by Odoo but you can change it "

addons/stock_account/models/account_invoice.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
-from odoo import api, models
+from odoo import api, models, fields
 
 import logging