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

Todd East
PLUS
Todd East
Courses Plus Student 3,602 Points
Posted by Todd East
Todd East
Courses Plus Student 3,602 Points

why does this code trip a ValueError?

def add(num1,num2): total=float(num1+num2) return(total)

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

1 Answer

jacksonpranica
jacksonpranica
17,610 Points
jacksonpranica
jacksonpranica
17,610 Points

Hey Todd,

Wasn't really sure what value error was occuring as it worked in my local python environment. However, when doing the code challenge I found where the problem lied.

So in the code challenge it says to turn your arguments into floats using float() BEFORE you add them. Meaning you should be doing:

def add(num1,num2):
    total=float(num1)+float(num2)
    return(total)

EDIT: just realized num1 and num2 are strings and thats why float(num1+num2) doesnt work because it makes one giant string that cant be turned into a float due to the + sign. Ignore the explanation below

So why is float(num1+num2) wrong? Well it seems in the code challenge the software is taking (num1+num2) as a string due to the + sign. So obviously a string of "num1+num2" cant be converted to a float because a "+" does not have a numeric value.

As i was saying, in my local python environment on my computer num1+num2 is completed and turned into a numeric value before they try to turn it into a float. Im not sure why the code challenge takes it as a string due to the +

Cheers