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

Functions in python

I don't understand where I am going wrong. It would be best if you described it as simple as possible as I am only 13. Thanks

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.

add_list([1, 2, 3])
Chris Freeman
Chris Freeman
Treehouse Moderator 68,033 Points

White Moses, one of the challenge purposes is to practice using a for loop. The function sum() has not yet been taught at this early stage of the course.

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,033 Points

Hi Michelle! Let's walk through the challenge.

Task 1 says "Make a function named add_list that takes a list. The function should then add all of the items in the list together and return the total. Assume the list contains only numbers. You'll probably want to use a for loop. You will not need to use input().

Step 1; "Make a function named add_list that takes a list...."

# making (or defining) a function is done with the keyword 'def' followed by
# the name of the function, the list of arguments, and a colon ':'. Here I am 
# choosing to call the argument 'lst' (I don't use 'list' since it's a builtin function name)
def add_list(lst):
    pass  #temporary code block for now....

Step 2: " The function should then add all of the items in the list together..."

# replacing the temporary code block 'pass' with loop to add the list items together
def add_list(lst):
    # set our current total to 0.
    total = 0
    # for each item in the passed-in argument 'lst'...
    for item in lst:
        # added each item to the total
        total = total + item

Step 3: "and return the total."

# Add return statement
def add_list(lst):
    # set our current total to 0.
    total = 0
    # for each item in the passed-in argument 'lst'...
    for item in lst:
        # added each item to the total
        total = total + item
    # return current total value
    return total

Thank you