'bool' object has no attribute 'startswith': (<type 'exceptions.AttributeError'>, AttributeError("'bool' object has no attribute 'startswith'",), <traceback object at 0x7fe239e4f440>)

I can't understand what this error means.

here's the code on my wizard:

def print_excel(self, data):

context = self._context

datas = {'ids': context.get('active_ids', [])}

datas['model'] = 'this.bank.info'

datas['form'] = self.read()[0]

return {'type': 'ir.actions.report.xml',

'report_name': 'bank_module.bank_summary.xlsx',

'datas': datas,

'name': 'Bank Summary'

}

This is from my report:

class BankSumXls(ReportXlsx):

def generate_xlsx(self, workbook, data, lines):

BankAdviceSumXls('report. bank_module.bank_summary.xlsx , 'this.bank.info')

I just want to print an atleast empty sheet for now. please help me. Thanks in advance