In  WORKED DAYS table i have 2 line

code ​ ​number_of_days

GLOBAL -​2

GLOBAL ​-1

and my code in 

Salary Rules, i create:

Amount Type: Python code

def get_total_days_global():

  total = 0

  for line in worked_days.GLOBAL:

    total += line.number_of_days

  return total

result = worked_days.GLOBAL and (contract.wage / worked_days.WORK100.number_of_days) * get_total_days_global()

This code get only number_of_days of line 2 ( number_of_days = -1)