__all__ = ['isnone', 'notnone', 'inc', 'dec', 'even', 'odd']


EMPTY = object() # Used as unique default for optional arguments


def isnone(x):
    return x is None

def notnone(x):
    return x is not None


def inc(x):
    return x + 1

def dec(x):
    return x - 1

def even(x):
    return x % 2 == 0

def odd(x):
    return x % 2 == 1

@@ -60,22 +60,90 @@
 %5D%0A%0A%0A
-EMPTY = object
+class EmptyType:%0A    def __repr__(self):%0A        return 'EMPTY'%0A%0AEMPTY = EmptyType
 () #

Make pretty EMPTY value