python - How do I check if a string is a number (float)?

What is the best possible way to check if a string can be
represented as a number in Python?

The function
I currently have right now is:

def
            is_number(s):
 try:
 float(s)

 return
            True
 except ValueError:
 return
            False

Which, not only
is ugly and slow, seems clunky. However I haven't found a better method because calling
float in the main function is even worse.