Question

Is there some function like str.isnumeric but applicable to float?

'13.37'.isnumeric() #False  

I still use this:

def isFloat(string):
    try:
        float(string)
        return True
    except ValueError:
        return False

Answer 1

As Imran says, your code is absolutely fine as shown.

However, it does encourage clients of isFloat down the “Look Before You Leap” path instead of the more Pythonic “Easier to Ask Forgiveness than Permission” path.

It’s more Pythonic for clients to assume they have a string representing a float but be ready to handle the exception that will be thrown if it isn’t.

This approach also has the nice side-effect of converting the string to a float once instead of twice.