The program shows how to to raise errors, as well as how to create a custom error.
The program will ask for a age value. If the value is not a number it re-asks the question. If the age is out of a given bounds a error is raised. The custom error is created as a class with another related error class as an inheritance.
Example:
> python get_age.py
> How old are you? as1
> Invalid integer? input
> How old are you? 31
> 31
> How old are you? 133
> Traceback (most recent call last):
> File "get_age.py", line 72, in
> print get_age1()
> File "get_age.py", line 42, in get_age1
> raise OutOfRangeError("The value", age, "Is out of the range 0 to 122")
> __main__.OutOfRangeError: ('The value', '133', 'Is out of the range 0 to 122')