Qweb-Odoo v8 -Error

嗨，我需要帮助这里咧嘴表情我需要从函数get_timetable获取值但是当我想打印报告时它说QWebException：“'NoneType'对象不可调用”而评估'get_timetable（o）'我不知道问题是什么

这是我的XMLreport视图

<table class="gridtable center">
                                     <tr t-foreach="get_timetable(o.many2one_connection.table_id)" t-as="a">

                                          <td >
                                              <span t-esc="a['start_time'] - a['end_time']" />
                                          </td>
                                         <td>
                                              <span t-esc="a.get('saturday') "/>
                                          </td>
                                          <td>
                                              <span t-esc="a.get('sunday')"/>
                                          </td>
                                         <td>
                                              <span t-esc="t.get('monday')"/>
                                          </td>
                                          <td>
                                              <span t-esc="t.get('tuesday')"/>
                                          </td>
                                          <td>
                                              <span t-esc="t.get('wednesday')"/>
                                          </td>
                                          <td>
                                              <span t-esc="t.get('thursday')"/>
                                          </td>
                                          <td>
                                              <span t-esc="a.get('friday')"/>
                                          </td>

                                      </tr>
                                </table>

这是我的.py文件

import time
from openerp.report import report_sxw
from openerp.osv import osv


class fci_timetable_report(report_sxw.rml_parse):
    def __init__(self, cr, uid, name, context=None):
        super(fci_timetable_report, self).__init__(cr, uid, name, context=context)
        self.localcontext.update({
            'time': time,
            'get_timetable':self._get_timetable,
        })
    def _get_timetable(self, timetable_id):
        timetable_detail=[]
        self.cr.execute("""select t.start_time,t.end_time,s.name,week_day,r.name as teacher from fci_time_table_line t, fci_subject_subject s, resource_resource r, hr_employee hr where t.subject_id= s.id and t.teacher_id= hr.id  and hr.resource_id = r.id  and table_id = %d group by start_time,end_time,s.name,week_day,r.name order by start_time"""%(timetable_id.id))
        res = self.cr.dictfetchall()
        self.cr.execute("""select start_time,end_time from fci_time_table_line where table_id=%d group by start_time,end_time  order by start_time"""%(timetable_id.id))
        time_data = self.cr.dictfetchall()
        for time_detail in time_data:
            for data in res:
                if time_detail['start_time']==data['start_time'] and time_detail['end_time']==data['end_time']:
                    if (data['name']=='Recess'):
                        time_detail[data['week_day']] = data['name']
                    else:
                        time_detail[data['week_day']] = data['name'] + '\n(' + data['teacher'] + '\n(' + data['subject']+ ')'
            timetable_detail.append(time_detail)
        return timetable_detail
class timetable_report_document(osv.AbstractModel):
    _inherit = 'report.abstract_report'
    _template = 'FCI_ERP.timetable_report_document'
    _wrapped_report_class = fci_timetable_report

我希望我能找到一些帮助