Hi I am trying to count no of days the employee signed in so to count no of presents in the office in a month

please help me

I am thinking if i iterate through the hr.attendance module to count no of days

class esteem_payslip(osv.osv):
_inherit = 'hr.payslip'

def prasent_days(self, cr, uid, ids, field_names, args, context=None):
    res={}
    user_att = self.pool.get("hr.attendance")
    for slip in self.browse(cu, uid, ids, context=None):
        temp = 0
        att_ids = user_att.search(cu, uid, [('employee_id','=',slip.employee_id.id)])        
        for count in user_att.browse(cu, uid, att_ids, context=None):
            if count.name  >= slip.date_from and count.name <= slip.date_to: #This is not a good condition
                temp = temp + 1.0
        res[id]=temp 
    return res

_columns = {
       'es_present':fields.function(prasent_days, "No.of Present Days"),           
}

esteem_payslip()

this is not working

att_ids = user_att.search(cr, uid, [('employee_id','=',slip.employee_id.id)]) NameError: global name 'cr' is not defined

def prasent_days(self, cu, uid, ids, field_names, args, context=None):
    res={}
    user_att = self.pool.get("hr.attendance")
    for slip in self.browse(cu, uid, ids, context=None):
        temp = 0
        att_ids = user_att.search(cr, uid, [('employee_id','=',slip.employee_id.id)])        
        for count in user_att.browse(cu, uid, att_ids, context=None):
            if count.name  >= slip.date_from and count.name <= slip.date_to: #This is not a good condition
                temp = temp + 1.0
        res[id]=temp 
    return res

_columns = {
       'es_present':fields.function(prasent_days, "No.of Present Days"),           
}