polypie

Python polymorphic function declaration with obvious syntax. Just use the same function name and mark each function definition with @polymorphic decorator.

Installation

pip install polypie

Requirements

• Python 3.5+
• typeguard (will be installed automatically)

Example

from typing import Any, Sequence

from polypie import polymorphic, PolypieException


@polymorphic
def example(a: int, b):
    print('(1)')


@polymorphic
def example(a: str, b: Any):
    print('(2)')


@polymorphic
def example(a: Sequence[str]):
    print('(3)')


example(100, 200)   # (1)
example('foo', 200)   # (2)
example(['foo'])   # (3)
example(('bar', 'baz'))   # (3)
try:
    example({'foo': 'bar'})
except PolypieException as exc:
    print(exc)   # Matching signature <...> not found


class Example:

    def __init__(self):
        self.values = {}

    @polymorphic
    def value(self, name):
        return self.values[name]

    @polymorphic
    def value(self, name, value):
        self.values[name] = value


instance = Example()
instance.value('foo', 100)
instance.value('bar', 'baz')
print(instance.value('foo'))   # 100
print(instance.value('bar'))   # baz

Tests

tox [-e ENV] [-- --cov]