singledispatch

#!/usr/bin/env python2
# encoding: utf-8

class singledispatch(object):
    __slots__ = (
            'resolver',
            'default',
            'last',
            )
    def __init__(self, func):
        self.resolver = {}
        self.default = func
        self.last = None

    def register(self, *signature):
        def wrapper(function):
            if isinstance(function, singledispatch):
                self.resolver[signature] = self.last
            else:
                self.resolver[signature] = function
                self.last = function
            return self
        return wrapper

    def __call__(self, *args):
        signature = tuple(map(type, args))
        func = self.resolver.get(signature, self.default)
        return func(*args)


@singledispatch
def echo(arg):
    print 'Fallback mode:',arg

@echo.register(float)
@echo.register(int)
def echo(number):
    print 'Number:', number

@echo.register(str)
def echo(text):
    print 'Text:', text

if __name__ == '__main__':
    echo(42)
    echo(3.14)
    echo('Testing')
    echo([1, 2, 3])