None - Represents no value

None is used to indicate "no value."  There are times when you may want to explicitly say "there is no value."

Example

Python
def divide(n, d):
    if d == 0:
        result = None
    else:
        result = n / d

return result

Output

2.0
None

Notes: In other languages, the term "null" is the equivalent of Python's None.