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

Posted by Zeus Intuivo
Zeus Intuivo
13,129 Points

Wrong exercise dynamic in Python lists

So it says it passes 3 elements but it wants to have 6 as an answer. the only way I see this working out was like this 

shopping_list = [] 

def add_list(items):
  for i in items: 
    shopping_list.append(i)
    shopping_list.append(i)

  return len(shopping_list)

Notice how I had to duplicate the ** append() **. It makes me thing the exercise if wrongly constructed.

4 Answers

Peter Szerzo
Peter Szerzo
22,661 Points
Peter Szerzo
Peter Szerzo
22,661 Points

It's a bit more involved than that. I'll give away part of the answer:

def add_list(items):
  sum = 0
  for item in items:
    # magic goes here
  return sum
Peter Szerzo
Peter Szerzo
22,661 Points
Peter Szerzo
Peter Szerzo
22,661 Points

Ani,

The expected number 6 is the sum of the three numbers, not the length of the list. Of course, if you force the length of the list to be 6 by adding every number in there twice and return this length, then you may pass the challenge. But this is pure coincidence.

Try implementing the sum of the list items by setting a sum variable to 0 at the beginning of the function, and adding each list item to it within to for loop (the one you already have).

Peter

Zeus Intuivo
Zeus Intuivo
13,129 Points
Zeus Intuivo
Zeus Intuivo
13,129 Points 
sum(items)

?

Zeus Intuivo
Zeus Intuivo
13,129 Points
Zeus Intuivo
Zeus Intuivo
13,129 Points 
...
    sum += item
...