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

Amr AbdelNasser
Amr AbdelNasser
1,745 Points
Posted by Amr AbdelNasser
Amr AbdelNasser
1,745 Points

combining functions and exceptions

can't figure out, how to add an exception with the set function without getting the "Task one is no longer valid" notification. Whats wrong with my code?

trial.py 
def add(e,r):
try:
    e=int(input)
    r=int(input)
except ValueError  
    return None
else:
    return (float(e)+float(r))

2 Answers

Gerald Wells
Gerald Wells
12,763 Points
Gerald Wells
Gerald Wells
12,763 Points 
def add(x,y):
    try:
        return float(x)+float(y)
    except ValueError:
        return None
Amr AbdelNasser
Amr AbdelNasser
1,745 Points
Amr AbdelNasser
Amr AbdelNasser
1,745 Points

that makes a lot of sense, but it still doesn't seem to work. Getting the same message of "Task 1 no longer passing" and i think the exercise requires an "else".

Gerald Wells
Gerald Wells
12,763 Points

No it works, I tried it.

Guillermo Del Molino
Guillermo Del Molino
2,967 Points
Guillermo Del Molino
Guillermo Del Molino
2,967 Points

Alright, I think I may have an answer

def add(a, b):
    try:
        return float(a) + float(b)
    except ValueError:
        return None
    else:
        return float(a) + float(b)

You´re basically using the else to repeat the first step in case it didn't work for any reason. I tried running it in the Code Challenge and it marked it as a correct solution.

Hope you understand, if not just tell me and I'll try to clarify for you.

Gerald Wells
Gerald Wells
12,763 Points

why are you returning the same thing in two different areas?? that is terrible advice.

Guillermo Del Molino
Guillermo Del Molino
2,967 Points

Quite true... So then it should work fine without it but I still don't understand what the code challenge means by using the else structure at the end. What should go on the else? I mean, I understand that the code works the same with or without the else but why is it part of the challenge to use else??

Gerald Wells
Gerald Wells
12,763 Points

else is english semantics except is the programatic representation when you are trying to trap an error.