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Python

Posted by Michael Leonard
Michael Leonard
1,279 Points

Having issues with python challenge

This is the script I wrote for the Python Basics Challenge test. 

my_list = [1, 2, 3]

def add_list(my_list):
    total = 0
    for item in my_list:
        total = total + item
        continue
    return(total)

totalnum = add_list(my_list)
print(totalnum)

total_sum = add_list(my_list)

def summarize(total_sum, my_list):
  print("The sum of {} is {}.".format(str(my_list), total_sum))


summarize(total_sum, my_list)

It runs perfectly in the terminal but when I check code in the workspace it gives me this error. "TypeError: summarize() missing 1 required positional argument: 'my_list'"

Any help is appreciated. Thanks!

Update:

Fixed it with this code:

def summarize(my_list)
   final_string = "The sum of {} is {}.".format(str(my_list), total_sum)
   return(final_string)

Not sure why i don't have to include total_sum in the function parameters.

Can somebody explain this?

Chris Freeman
Chris Freeman
Treehouse Moderator 68,332 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,332 Points

The challenge is supposed to require the function summarize() call the function add_list() to get the correct results. It may be a bug in how the grader is evaluating your code that is letting it pass when you create a global with the results of add_list. Tagging Kenneth Love

1 Answer

Ratik Sharma
Ratik Sharma
32,885 Points
Ratik Sharma
Ratik Sharma
32,885 Points

You don't have to include total_sum in the function parameters because in your script, you've defined total_sum outside any block of code (for instance, a function) and Python treats it as a variable with global scope (ie, it can be accessed anywhere in the script). And that's why summarize() doesn't require it as a parameter.

Also, the challenge just requires you to just create two functions. You don't need to create a list and pass it into the functions.

Here is how I would write this script: 

def add_list(my_list):
    total = 0
    for item in my_list:
        total += item  # this is equivalent to total = total + item
        # the `continue` isn't really required
    return(total)


def summarize(my_list):
    print("The sum of {} is {}.".format(str(my_list), add_list(my_list)))
Michael Leonard
Michael Leonard
1,279 Points

Thanks Ratik! That clears it up for me.