Please, i have this code  

def evaluate_transport(self):
		print "computing transport information"
		total_expense_no_affect_salary = 0
		total_expense_affects_salary = 0
		total_income = 0
		for i in self:
			for j in i.transport_invoice_ids:
				total_income += j.inc_amount
				if j.affects_salary:
					total_expense_affects_salary += j.exp_amount
				else:
					total_expense_no_affect_salary += j.exp_amount
			i.total_expense = total_expense_no_affect_salary + total_expense_affects_salary
			i.total_expense_no_affect_salary = total_expense_no_affect_salary
			i.total_expense_affects_salary = total_expense_affects_salary
			i.total_income = total_income
			print str(i.total_income) + " \n"
			print str(i.total_expense) + " \n"
			print str(i.total_expense_no_affect_salary) + " \n"
			print str(i.total_expense_affects_salary) + " \n"
		print "Done with total income and total expense"

Uncaught Error: QWeb2 - template['ShowPaymentInfo']: No enumerator given to foreach

http://192.168.1.122:8069/web/static/lib/qweb/qweb2.js:48
Traceback:
Error: QWeb2 - template['ShowPaymentInfo']: No enumerator given to foreach
    at Object.QWeb2.tools.exception (http://192.168.1.122:8069/web/static/lib/qweb/qweb2.js:48:19)
    at Object.QWeb2.tools.foreach (http://192.168.1.122:8069/web/static/lib/qweb/qweb2.js:195:22)
    at Engine.eval (eval at <anonymous> (http://192.168.1.122:8069/web/static/lib/qweb/qweb2.js:404:33), <anonymous>:20:23)
    at Engine.QWeb2.Engine.QWeb2.tools.extend._render (http://192.168.1.122:8069/web/static/lib/qweb/qweb2.js:393:58)
    at Engine.QWeb2.Engine.QWeb2.tools.extend.render (http://192.168.1.122:8069/web/static/lib/qweb/qweb2.js:385:26)
    at OdooClass.form_common.AbstractField.extend.render_value (http://192.168.1.122:8069/account/static/src/js/account_payment_widget.js:24:32)
    at OdooClass.<anonymous> (http://192.168.1.122:8069/web/static/src/js/views/form_common.js:704:22)
    at OdooClass.Class.extend.trigger (http://192.168.1.122:8069/web/static/src/js/framework/mixins.js:222:31)
    at OdooClass._.extend.trigger (http://192.168.1.122:8069/web/static/src/js/framework/mixins.js:272:42)
    at http://192.168.1.122:8069/web/static/src/js/framework/mixins.js:338:22

I have not used any javascript code. 

I have a transport.invoice and transport.invoice.line model, following same way account.invoice and account.invoice.line is implemented. 

    Want to sum all income and expense(determined by a checkbox) items on the transport.invoice.line 

Please, any help. 

Am still new to odoo so sorry if i have wrong convention.