fabiommendes/sidekick

=======================
``sidekick.properties``
=======================

Functions in this module are helpers intended to create convenient and
declarative idioms when declaring classes. Perhaps it is not entirely correct
calling them "functional", but since some patterns such as lazy properties
are common in functional libraries, Sidekick has a module for doing that.

This library can be installed independently from the rest of sidekick distribution
using ``pip install sidekick-properties``. Prefer depending on sidekick-properties
if your project only use those functions.

Quick start
===========

.. code-block:: python

    from typing import NamedTuple
    from sidekick.properties import lazy, alias, delegate_to  # or from sidekick.api import *


    class Person(NamedTuple):
        name: str
        age: int
        full_name = alias('name')

    p = Person('Karl Heinrich', age=29)

Now ``p.full_name`` is now an alias to ``p.name``. This usage simply exposes an attribute
under a different name. :py:func:`alias` can be configured in many different ways by choosing mutability
and simple transformations between the exposed alias and the original attribute.

.. code-block:: python

    class Employee(NamedTuple):
        person: Person
        role: str
        name = delegate_to('person')
        age = delegate_to('person')

        @lazy
        def photo(self):
            return download_from_server(f'http://url.img/employees/{self.name}')