for the challenge task how would I use a for loop to sum individual items in a list? I used the sum(item) function.

Hi Matthew

The way I approached this is to create a variable to hold the running total then loop through the numbers in the list adding them to the running total. Then after the for loop has finished running through the numbers in the list return the total.

def function(the_list):
    total = 0
    for num in the_list:
        total += num
    return total

I've avoided using the exact names from the challenge but it should work just the same.

Hope it helps!

I tried the above but I keep getting the error that the return is None rather than the total. Here is my code <p> def add_list(the_list):<br> total = 0<br> for i in the_list:<br> total += int(i)<br> return total<br>

def summarize(the_list):<br> print("The sum of ", the_list, " is ", add_list(the_list))<br> </p>

OK so the challenge states to assume that the list only contains numbers so there's no need to cast the items from the list into the int() function but that actually still works it's just unnecessary.

The error actually lies with the summarize function rather than the add_list function.

In the first place remember to return the string statement not to print it.

Also you have to use string formatting (as discussed in the video below) to put it together otherwise it will still fail as it doesn't return a single string. http://teamtreehouse.com/library/python-basics/ins-outs/string-formatting

It should take the format of below:

return "The sum of {} is {}.".format(the_list, add_list(the_list))

Hope it helps!