diff --git a/addons/account/invoice.py b/addons/account/invoice.py
index 3987d190f16..fb25b7b8f02 100644
--- a/addons/account/invoice.py
+++ b/addons/account/invoice.py
@@ -497,7 +497,7 @@ class account_invoice(osv.osv):
             total_currency = 0
             key_line=[]
             for i in iml:
-                if i.has_key('account_id') and i.has_key('taxes'):
+                if 'account_id' in i and 'taxes' in i:
                     if not (i['account_id'],i['taxes']) in key_line:
                         key_line.append((i['account_id'],i['taxes']))
                 if inv.currency_id.id != company_currency:
@@ -528,7 +528,7 @@ class account_invoice(osv.osv):
                 if acc_obj.browse(cr,uid,item[0]).merge_invoice:
                     repeat=False
                     for move_line in iml:
-                        if (move_line.has_key('account_id') and move_line['account_id']==item[0]) and (move_line.has_key('taxes') and move_line['taxes']==item[1]):
+                        if (move_line.has_key('account_id') and move_line['account_id']==item[0]) and ('taxes' in move_line and move_line['taxes']==item[1]):
                             move_list.append(move_line)
                             if repeat:
                                 for key in move_line:
@@ -820,7 +820,7 @@ class account_invoice(osv.osv):
         types = {'out_invoice': -1, 'in_invoice': 1, 'out_refund': 1, 'in_refund': -1}
         direction = types[invoice.type]
         #take the choosen date
-        if context.has_key('date_p') and context['date_p']:
+        if 'date_p' in context and context['date_p']:
             date=context['date_p']
         else:
             date=time.strftime('%Y-%m-%d')