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

Marko Jakovljevic
Marko Jakovljevic
1,286 Points
Posted by Marko Jakovljevic
Marko Jakovljevic
1,286 Points

ValueError: could not convert string to float: '2.25.2'

Seem to be having an error here when trying this out. The code compiles fine and adds a floating decimal point when I run this through my compiler

Not sure why it's coming up as a string? Have tried int() and have also tried to run float(num1) float(num2)

prior to the return

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

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,454 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points

If the arguments are strings, using float(num1 + num2), will concatenate the strings before trying to convert. Try this:

def add(num1,num2):
  return float(num1) + float(num2)
Melanie Villela
Melanie Villela
3,048 Points
Melanie Villela
Melanie Villela
3,048 Points

Hello Chris,

Can you also write:

def add float(num1, num2):
    return (num1 + num2)
Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points

Hi Melanie, the simple answer is no because it is a syntax error in the definition of a function.

The complicated answer is there is an advanced python feature called decorators where you can wrap a function with another function. This wrapping function can convert the passed arguments to other types such as floats.

You will see this when you reach the Flask Basics course. The @app.route() decorator can cast values from the URL into ints and floats.