error:

File "c:\program files (x86)\odoo 12.0\server\odoo\addons\assignments_report\report\assignment_report.py", line 45, in get_objects
    dict[line.student_id.name][0].update(codes)
IndexError: list index out of range

Error to render compiling AST
IndexError: list index out of range
Template: 1016
Path: /templates/t/t/t/div/div/t/table[2]/tbody/tr
Node: <tr t-foreach="get_objects(docs)" t-as="a">

                                            <td class="text-center">
                                                <span t-esc="a_index+1"/>
                                            </td>
                                            <td class="text-left">
                                                <span t-raw="'%s' %  a_value if  a_value else''"/>

                                            </td>
                                            <t t-set="total_marks" t-value="0"/>
                                            <td t-foreach="a_value" t-as="lines">
                                                <t class="text-right">

<!--                                                    <span t-raw="'%s' %  lines[a_index] if  lines[a_index] else''"/>-->
                                                    <!--<t t-set="total_marks"
                                                       t-value="total_marks + a_value[lines_index]"/>-->

                                                </t>

                                            </td>
                                            <td>
                                                <span>
                                                    <t t-esc="total_marks"/>
                                                </span>
                                            </td>


                                        </tr>


                                    

def get_objects(self, records):
    dict = {}
    for object in records:

        for line in object.assignment_sub_line:
            marks1 = []
            codes={}
            if line.student_id.name not in dict:
                #marks1.append(line.marks)
                codes[line.assignment_id.assignment_type_id.code] = line.marks
                marks1.append(codes)
                dict[line.student_id.name]=marks1
                marks1.clear()
                codes.clear()
            if line.student_id.name in dict:
                codes[line.assignment_id.assignment_type_id.code] = line.marks
                dict[line.student_id.name][0].update(codes)
                codes.clear()

    return dict

the error is here 

 dict[line.student_id.name][0].update(codes)

please give me solution