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Python Python Basics (Retired) Putting the "Fun" Back in "Function" Functions

Posted by chevano gordon
chevano gordon
3,399 Points

need help not sure i know what to do

functions.py 
# add_list([1, 2, 3]) should return 6
# summarize([1, 2, 3]) should return "The sum of [1, 2, 3] is 6."
# Note: both functions will only take *one* argument each.
my_list = []

def add_list(items):
 my_list.append(item)
total = 0
total+=my_list[]
return total

[edited format --cf]

1 Answer

Cory Madden
Cory Madden
7,120 Points

You need to write two different functions. One that adds all the list items and returns the sum, and another that uses that function and returns a string.

def add_list(some_list):
  sum = 0
  for item in some_list:
    sum += item;
  return sum

And your second function will be:

def summarize(some_list):
  return "The sum of {} is {}".format(some_list, add_list(some_list))
chevano gordon
chevano gordon
3,399 Points

what is item. is it a key word or is it define somewhere else in the code and if it is what is its purpose in the code. thank you for the help

Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

An "item", sometimes called an "element", is a generic term for what is contained within a list or other python container.

Cory Madden
Cory Madden
7,120 Points

item is just a variable we create on the spot in a for loop.The word "item" in this case could be anything. So on each loop it increments the index of the value it holds. On the first loop in:

for item in [1, 2, 3]:
  print(item)

The output will be 1, and then on the next iteration it will be 2.

It's similar to writing:

some_list = [1, 2, 3]
i = 0
while i < len(some_list) - 1:
  print(some_list[i])
  i += 1
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

Sometimes "item" is used as a variable name. In this case it represents what ever object is assigned to it.