search method compare of current date which is date format with date_open is crm_lead field which is string format how to do that

def get_name(self, form):       
    crm_obj = self.pool.get('crm.lead')
    sale_obj=self.pool.get('hr.employee')
    line=[]
    d = datetime.now().date()
    currentdate=time.strftime('%Y-%m-%d')
    cur_date=datetime.strptime(currentdate,'%Y-%m-%d')
    line=crm_obj.browse(self.cr, self.uid, self.ids)
    targetselect=form['target_selection']
    for val in line:
        nameop=val.date_open
        cdate=datetime.strptime(nameop,'%Y-%m-%d %H:%M:%S').date()                      
        gval=val.id
    print type(nameop),cdate,type(cdate),gval,cur_date,targetselect,d,"hhhhhhhhhhhhhhhhhhhhhhhhhhh"
    if targetselect=='daily':
        print cdate,d,"111111111111111111111111111111"          
        lines=crm_obj.search(self.cr, self.uid, [('date_open','==',d)])
        print lines
    else:
        raise osv.except_osv(_('Info'),_('There is no entry for today'))    
        print x