A lightweight, very convenient function to dynamically create good enums in Python

enum.py

# Makes an enum class with instances (class attributes) having uppercase 
# names while the string representations can be in any case. For example, 
# Color = enum_class('Color', 'red', 'amber', 'green') returns class Color
# with members Color.RED, Color.AMBER, and Color.GREEN. The __str__ instance 
# methods produce 'red', 'green', and 'blue', respectively. To get the 
# instance from the string, use, for example, Color.from_string('blue'), 
# which will return Color.BLUE.

def enum_class(classname, *values):
    cls = type(classname, (), {})
    cls._mapping = {}
    for value in values:
        attribute = value.upper().replace(' ', '_')
        instance = cls()
        setattr(cls, attribute, instance)
        instance.value = value
        cls._mapping[value] = instance
    cls.from_string = lambda value: cls._mapping.get(value)
    cls.__str__ = lambda self: self.value
    return cls

Why not just use the Enum class in Python? docs.python.org/3/library/enum.html

At the time I wrote this I was not aware that enums were callable.