Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Python Python Sequences Sequence Iteration Iterating over Ranges

Timothy Maycock
PLUS
Timothy Maycock
Courses Plus Student 3,346 Points

Why "NONE"

My code passes the check yet when I run it through VSC it returns NONE as the values. Tried googling it to understand why this happens but couldn't get a good answer. Any help in understanding this would be greatly appreciated.

Cheers

iterating_ranges.py
my_list = []

for i in range(10):
    print(my_list.append(i))

1 Answer

Jennifer Nordell
seal-mask
STAFF
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher

Hi there, Timothy Maycock! The code challenge itself doesn't ask you to print anything. What you're doing here, is printing the result of the .append method. That method adds an item to a list, but it has a return type of None.

But if you modified what and where you are printing, then your results would be wildly different.

Try this:

my_list = []

for i in range(10):
    my_list.append(i)

print(my_list)

Hope this helps! :sparkles:

Timothy Maycock
Timothy Maycock
Courses Plus Student 3,346 Points

Hi Jennifer

Ok. With your explanation and code snippet I see where I went wrong. Happy I asked as when I clicked the check work button, it gave me a passing result, even though my code was the wrong solution.

Thanks for clarifying it for me

Cheers