In case you are looking for parsing (positive, unsigned) integers instead of floats, you can use the isdigit() function for string objects.
>>> a = “03523”
>>> a.isdigit()
True
>>> b = “963spam”
>>> b.isdigit()
False
String Methods – isdigit(): Python2, Python3
There’s also something on Unicode strings, which I’m not too familiar with
Unicode – Is decimal/decimal
Which, not only is ugly and slow
I’d dispute both.
A regex or other string parsing method would be uglier and slower.
I’m not sure that anything much could be faster than the above. It calls the function and returns. Try/Catch doesn’t introduce much overhead because the most common exception is caught without an extensive search of stack frames.
The issue is that any numeric conversion function has two kinds of results
A number, if the number is valid
A status code (e.g., via errno) or exception to show that no valid number could be parsed.
C (as an example) hacks around this a number of ways. Python lays it out clearly and explicitly.
I think your code for doing this is perfect.