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Devin Bartley
Devin Bartley
2,800 Points

String Formatting With Dictionaries - Why is my answer not accepted?


I am stuck on the String Formatting With Dictionaries task. The strange thing is that if I run the script, the output comes out correct, but the challenge software seems to think there is an error.

The challenge asks for this:

Create a function named string_factory that accepts a list of dictionaries and a string. Return a new list build by using .format() on the string, filled in by each of the dictionaries in the list.

Here is my script:

dicts = [
    {'name': 'Michelangelo',
     'food': 'PIZZA'},
    {'name': 'Garfield',
     'food': 'lasanga'},
    {'name': 'Walter',
     'food': 'pancakes'},
    {'name': 'Galactus',
     'food': 'worlds'}

string = "Hi, I'm {name} and I love to eat {food}!"

list = []

newdict = {}

def string_factory(dicts, string):
  for item in dicts:
    newdict = item
  return list

And the error that comes out is this:

<b>isinstant() arg 2 must be a type or a tuple of types!</b>

2 Answers

Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

The variable list is not initialized (it is also a function list()). So in your code, your are calling the builtin list.append() function, that needs a list to operate upon. In short you need to add a list = [] above your for loop.

That said, using list as a variable name is not the best as it collides with the builtin function list(). Technically you could also get your code to work by initializing foo = [], then use:

    list.append(foo, string.format(**newdict))
return foo

But that's way off target and not good coding.

In summary, try:

def string_factory(dicts, string):
    mylist = []
    for item in dicts:
        newdict = item
    return mylist
Devin Bartley
Devin Bartley
2,800 Points

Thank you so much, Chris. This is very helpful!

I now understand why it wasn't working.

Have a great day!