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 Basics (2015) Logic in Python Try and Except

Jt Miller
Jt Miller
1,242 Points

Functions,Floats,try block

This is the question.

You're doing great! Just one more task but it's a bigger one. Right now, we turn everything into a float. That's great so long as we're getting numbers or numbers as a string. We should handle cases where we get a non-number, though. Add a try block before where you turn your arguments into floats. Then add an except to catch the possible ValueError. Inside the except block, return None. If you're following the structure from the videos, add an else: for your final return of the added floats.

trial.py
try:
def add(num1,num2):
    num1 = float(num1)
    num2 = float(num2)
    return(num1 + num2)

else:
    print(num1)
    print(num2)

except ValueError:
    return(none)

1 Answer

Rich Zimmerman
Rich Zimmerman
24,062 Points

Right now you're try/except/else block is out of order and you're defining your function inside of it.

def do_a_thing(thing):
    try: 
        # try to do the thing
        return thing
    except ValueError:
        # if the thing is a value error...
        # do whatever this block says
        print("thing is wrong!")
    else:
        # else do this block
        print("thing was wrong but not a ValueError")