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

Ali Asmee
Ali Asmee
1,404 Points
Posted by Ali Asmee
Ali Asmee
1,404 Points

Need help please.

Challenge Task 3 of 3

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 
def add(x, y)
    try:
        a = float(x)  
        b = float(y)
    except ValueError:
        return None
     else:
        return True

5 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

The colon (:) is missing from the function statement:

def add(x, y)::  # <-- added colon
    try:
        a = float(x)  
        b = float(y)
    except ValueError:
        return None
    else:  # <-- fixed else indent
        return a + b
Nathan Tallack
Nathan Tallack
22,159 Points
Nathan Tallack
Nathan Tallack
22,159 Points

Great work! Just a few little bugs. Comments below inline with your code.

def add(x, y):  # Don't forget the : here.
    try:
        a = float(x)  
        b = float(y)
    except ValueError:
        return None
    else:  # This was indented one space further than the code blocks above, take care with this.
        return a + b  # Need to return the addition result.
Zachary Martin
Zachary Martin
3,545 Points
Zachary Martin
Zachary Martin
3,545 Points

I got stuck on this challange and I ended up copying and pasting your code even though mine was virtually the same, only difference is that I called the scrpit at the end when you didn't and yours worked and mine didn't. that confuses me.

Ali Asmee
Ali Asmee
1,404 Points
Ali Asmee
Ali Asmee
1,404 Points

Thanks ill give it a try

Ali Asmee
Ali Asmee
1,404 Points
Ali Asmee
Ali Asmee
1,404 Points

Thank you both code worked...

ebinezer shamba
ebinezer shamba
348 Points
ebinezer shamba
ebinezer shamba
348 Points

Challenge Task 3 of 3 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.

def add(num1,num2):
    num1 = float(num1)
    num2 = float(num2) 
try: 
    num1 = float(num1)
    num2 = float(num2) 
except ValueError:
    return None
 else:
    return  num1 + num2

PLIZ HELP ....WHERE SHOULD I CORRECT

[MOD: added ```python formatting -cf]

Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

You are very close! The try statement needs to be indented to be inside the function. Also make sure the try, except, and else align.

Post back if you need more help. Good luck!!!