Python function overloading

>>> from multipledispatch import dispatch
>>> from collections import namedtuple
>>> from types import *  # we can test for lambda type, e.g.:
>>> type(lambda a: 1) == LambdaType
True

>>> Sprite = namedtuple('Sprite', ['name'])
>>> Point = namedtuple('Point', ['x', 'y'])
>>> Curve = namedtuple('Curve', ['x', 'y', 'z'])
>>> Vector = namedtuple('Vector', ['x','y','z'])

>>> @dispatch(Sprite, Point, Vector, int)
... def add_bullet(sprite, start, direction, speed):
...     print("Called Version 1")
...
>>> @dispatch(Sprite, Point, Point, int, float)
... def add_bullet(sprite, start, headto, speed, acceleration):
...     print("Called version 2")
...
>>> @dispatch(Sprite, LambdaType)
... def add_bullet(sprite, script):
...     print("Called version 3")
...
>>> @dispatch(Sprite, Curve, int)
... def add_bullet(sprite, curve, speed):
...     print("Called version 4")
...

>>> sprite = Sprite('Turtle')
>>> start = Point(1,2)
>>> direction = Vector(1,1,1)
>>> speed = 100 #km/h
>>> acceleration = 5.0 #m/s**2
>>> script = lambda sprite: sprite.x * 2
>>> curve = Curve(3, 1, 4)
>>> headto = Point(100, 100) # somewhere far away

>>> add_bullet(sprite, start, direction, speed)
Called Version 1

>>> add_bullet(sprite, start, headto, speed, acceleration)
Called version 2

>>> add_bullet(sprite, script)
Called version 3

>>> add_bullet(sprite, curve, speed)
Called version 4

Source: stackoverflow.com

Python function overloading

registry = {}


class MultiMethod(object):
    def __init__(self, name):
        self.name = name
        self.typemap = {}

    def __call__(self, *args):
        types = tuple(arg.__class__ for arg in args)  # a generator expression!
        function = self.typemap.get(types)
        if function is None:
            raise TypeError("no match")
        return function(*args)

    def register(self, types, function):
        if types in self.typemap:
            raise TypeError("duplicate registration")
        self.typemap[types] = function


def multimethod(*types):
    def register(function):
        name = function.__name__
        mm = registry.get(name)
        if mm is None:
            mm = registry[name] = MultiMethod(name)
        mm.register(types, function)
        return mm

    return register

###### usage ######
from multimethods import multimethod

# 'overload' makes more sense in this case
overload = multimethod


@overload(str, int)
def do_smth(a, b):
    print(a + b)


@overload(str)
def do_smth(a):
    print(a)

Source: stackoverflow.com

Similar codes

0 vote136 views1 answer
Make sure text is on page selenium python
Python
0 vote147 views1 answer
Print elements without print function in python
Python
12 votes159 views6 answers
Remove empty strings from list python
Python
0 vote123 views1 answer
Gyp err! stack error: command failed: c:\python39\python.exe -c import sys; print "%s.%s.%s" % sys.version_info[:3];
Python
2 votes137 views1 answer
Save file python tkinter
Python
107 votes125 views6 answers
Python rename columns
Python
2 votes130 views1 answer
Pytplot arc
Python
13 votes135 views2 answers
Sys get current pythonpath
Python
0 vote161 views1 answer
Python requests token x-www-form-urlencoded
Python
0 vote238 views1 answer
Modify a list with for loop and range function in python
Python