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

Python Basics- functions

Hey guys, I don't understand why my Python code is not working properly. Is my syntax wrong? Can't I call another function within another function? Thank you!

So basically the first question is: 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().

My code:

def add_list(list):
  return total

But the second one tells us to make a function summarize() that takes the list and prints "The sum of X is Y", where X is the list and Y is the sum. This is where my code does not work.

My code (below the first one):

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

4 Answers

Chris Freeman
Chris Freeman
Treehouse Moderator 68,404 Points

In the line

  print "The sum of {} is {}".format(list,  add_list(list))

The .str() is unnecessary. The .format() method does the conversion to a string automatically.

The other suggestions of not using the built-in type list as a variable name and to use a loop instead of the built-in function some are also valid but aren't causing the error.

Josh Keenan
Josh Keenan
19,652 Points

Try to avoid using 'list' as an argument name, it is a reserved word and in certain IDEs it can cause problems as it thinks you're trying to call the list() function, use my_list or list1, I stick to simple things like that normally!

Krzysztof Kucharzyk
Krzysztof Kucharzyk
Front End Web Development Techdegree Student 4,005 Points

Hmm I think you should do something like this:

def add_list(lst) :
  result = 0
  for item in lst:
    result += item
  return result

And for 2nd part define summarize with lst value and then return:

def summarize(lst):
  return "The sum of " + str(lst) + " is " + str(add_list(lst)) + "."

Thank you so much! :)