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

Posted by Andrew Joseph
Andrew Joseph
985 Points

I have no clue what i'm doing wrong

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.

^ is the question.

however, I have no idea what is happening, or what's wrong with my code, as i'm only getting a "Try again!" message.

Help with my code would be well appreciated. thanks.

trial.py 
def add(x, y):
try:
    x = int(input("number 1"))
    y = int(input("number 2"))
except ValueError:
    print("That isn't number")
    return None
else:
    return(x)
    return(y)

  a = float(x)
  b = float(y)
  print (a + b)

2 Answers

Anish Walawalkar
Anish Walawalkar
8,534 Points
Anish Walawalkar
Anish Walawalkar
8,534 Points

Just a few pointers:

  1. In your function add(x, y) you are being passed values for x and y, hence you don't need to input them
  2. In your try block you need to covert x and y into floats by using float() function, add them up and return the result
  3. If x or y cannot be converted to floats, python will throw a ValueError exception at which point it will enter the except block where you need to return None

in code it looks like this:

def add(x, y):
    try:
        return float(x) + float(y)
    except ValueError:
        return None

Hope that helps

Josh Keenan
Josh Keenan
20,315 Points
Josh Keenan
Josh Keenan
20,315 Points

Hi Andrew, here's my solution, apologies for the poor formatting!

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

santhosh gattu
santhosh gattu
551 Points

Thanks