dpx - 9 months ago 27

Python Question

I'm trying to get some help in returning values from "year_calc" function below (Python 3.5). In essence, the code works for returning "b" as I need a new starting value for "b" to be passed to "year_calc" for each iteration - I can get that to work just fine. However, I want the "total_cost" value from each year_calc iteration to be returned and added up until finished. Note the "grand_total" under the while loop. I realize this doesn't work as stated - just adding it so it may add clarity to what I'm attempting to accomplish. I am just not sure how to pull a specific value which is being returned. Any insight?

`def main():`

archive_total = float(input('Enter archive total (GB): '))

transfer_rate = float(input('Enter transfer rate (Gbps): '))

days_to_transfer = ((((archive_total*8/transfer_rate)/60)/60)/24)

xfer_per_day = archive_total/days_to_transfer

day_cost = xfer_per_day * 0.007 / 30

days = 365

total_days = 0

sum = 0

b = xfer_per_day * 0.007 / 30

total_years = 1

grand_total = 0.0

total_cost = 0.0

while total_years < years_to_transfer + 1:

b = year_calc(day_cost, days, total_days, sum,b,total_years,total_cost)

total_years += 1

grand_total += total_cost

def year_calc(day_cost,days,total_days,sum,b,total_years,total_cost):

while total_days < days -1:

b += day_cost

sum += b

total_days += 1

total_cost = sum + day_cost

print('Year',total_years,'cost: $', format(sum + day_cost, ',.2f'))

return (b, total_cost)

main()

Answer

`year_calc`

, as with any function that returns multiple items, will return its values in a tuple. Therefore, you can just change this line:

```
b = year_calc(day_cost, days, total_days, sum,b,total_years,total_cost)
```

to this one:

```
b, total_cost = year_calc(day_cost, days, total_days, sum,b,total_years)
```

This works because of how Python handles multiple assignment:

```
>> a, b = 1,2
>> print a
1
>> print b
2
```

As an aside, you should try to avoid using builtin names like `sum`

for your variables. And I'm not sure what `years_to_transfer`

is - do you define that elsewhere in your code?