Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Python Basics (2015) Logic in Python Try and Except

Function not defined - NameError: name 'add' is not defined

My function works fine without adding the try/except/else blocks. However, after I added the block; the code fails with the error "NameError: name 'add' is not define. I recall that NameError occurs when something is not defined (i.e. variable or the function in my case).

I cannot see where my mistake is. Any help would be great!

trial.py
def add (num1, num2):
  try:
    total = float(num1) + float(num2)
  except ValueError:
    return none
  else:
    return total

1 Answer

Michael Kelly
Michael Kelly
4,965 Points

Hi Joaquim,

I think you need to capitalize 'None'. The code as you have it will crash if you try add('1', '2')

Thank you very much for your help! That was the issue. Much appreciated!

Nick Lenzi
Nick Lenzi
7,979 Points

Thank you so much! This was driving me nuts! It seems like everytime I struggle with these challenges its always some stupid capitalization mistake or the grader being to picky out of technicality.

THANK YOU. I thought I was going crazy.