I have this table student_resources and here are data that it hold:

p_id   p_name     res_code         tax       base_amt    date
2300  |A student |WC158 - EWT 1%  |133.93   |13392.86   |2015-07-01
2300  |A student |WC158 - EWT 1%  |62.50    |6250.00    |2015-07-01
901   |B student |WC158 - EWT 1%  |8.31     |830.58     |2015-06-09
2831  |C student |WC160 - EWT 2%  |2736.84  |136842.11  |2015-06-04
905   |D student |WC158 - EWT 1%  |31.25    |3125.00    |2015-06-16
905   |D student |WC158 - EWT 1%  |31.25    |3125.00    |2015-06-29
905   |D student |WC158 - EWT 1%  |31.25    |3125.00    |2015-06-29
905   |D student |WC158 - EWT 1%  |26.79    |2678.57    |2015-06-16
959   |G student |WC158 - EWT 1%  |114.29   |11428.57   |2015-01-10
959   |G student |WC158 - EWT 1%  |478.90   |47890.18   |2015-01-20
2424  |L student |WC158 - EWT 1%  |45.54    |4553.58    |2015-03-03 

and in my class student_resources_report i have this definition:

...        
        atc_code = nature = ''
        _logger.info("\n\t\t\tI was called. My method name is %s"%(str('generate_student_resource_report')))
        base = amount = percent = 0.00
        for ewt in self.browse(cr,uid,ids,context):
            old_history = stud_re_report_line_obj.search(cr, uid, [('parent_id','=',ewt.id)],context=context)
            if old_history:
                  stud_re_report_line_obj.unlink(cr, uid, old_history,context=context)

            lines = student_resource_obj.search(cr, uid,[('date', '>=', ewt.date_from),('date', '<=', ewt.date_to)])

            for resource in student_resource_obj.browse(cr,uid,lines,context=context):
                if 'WC158' in resource.name:
                    atc_code = 'WC158'
                    nature = 'NOTBOOK'
                    seq = 1
                    base += resource.base_amount
                    amount += resource.tax_amount
                elif 'WC160' in resource.name:
                    atc_code = 'WC160'
                    nature = 'BACKPACK'
                    base += resource.base_amount
                    amount += resource.tax_amount
                    seq = 2
                elif 'WC010' in resource.name:
                    atc_code = 'WC010'
                    nature = 'COLOR'
                    base += resource.base_amount
                    amount += resource.tax_amount
                    seq = 3
                elif 'WC140' in ait.name:
                    atc_code = 'WC140'
                    nature = 'BOOKS'
                    base += resource.base_amount
                    amount += resource.tax_amount
                    seq = 4            
 percent = self._get_percentage(cr, uid, ids, resource.name, context=context)
                partner_id = resource.partner_id.id
                dictionary = {
                         'name' : ewt.id,
                         'parent_id' : ewt.id,
                         'partner_id' : partner_id,
                         'atc_code' : atc_code,
                         'nature' : nature,
                         'base_amt' : base,
                         'percent' : percent,
                         'tax_amt' : amount,
                         'seq' : seq,
                         }
                stud_re_report_line_obj.create(cr, uid, dictionary, context=context)
            list = stud_re_report_line_obj.search(cr,uid,[('parent_id','=',ewt.id)])
 lines = [line.id if line.id else False for line in stud_re_report_line_obj.browse(cr,uid,list,context=context)]
        value = {
                 "value" : {
                            'name' : 'Student Resource Report',
                            "ewt_line" : lines
                            }
                 }
        return value 

What i can't understand is that when my view is being rendered it output only looks like this:

Seq Stud        Code    Nature      Base Amt   Percent  Tax
1   B student   WC158   NOTEBOOK    830.58     1.0     8.31
1   D student   WC158   NOTEBOOK    3509.15    1.0     35.10 ---> (it adds 2678.57 and 830.58, which must not because it's p_id(student) is not the same (I don't know why)) 
2   C student   WC160   BACKPACK    136842.11  2.0     2736.84 

What i expected was the figure below and this is my desired output, that is to get the sum of all base_amt and tax_amt of particular student :

Seq Stud        Code    Nature      Base Amt   Percent  Tax
1   B student   WC158   NOTEBOOK    830.58     1.0     8.31
1   D student   WC158   NOTEBOOK    12053.57   1.0     120.54  ----> since (3125.00+3125.00+3125.00+2678.57) = 12053.57 and (31.25+31.25+31.25+26.79) =  120.54
2   C student   WC160   BACKPACK    136842.11  2.0     2736.84

Actually, this is somehow related with my 2 previous questions, but used sql statement instead and i get another error.

Any help/suggestions/comments is very much appreciated