Delegable is a simple Python alternative to Ruby on Rails' delegate module, which makes delegation easy. It enables any class to delegate its functions to an instance of another one. Here's an example:
@delegable
class Que:
def __init__(self):
self.q = []
self.delegate('append', 'pop', to='q')
que = Que()
que.append(1)
que.pop()
# => 1- Inheritance Safe
- No dependent libraries
- Available for py35, py36, py37, py38
pip install delegablePlace @delegable.delegator on the top of a class in which you want to enable delegation.
import delegable
@delegable.delegator
class Que:
def __init__(self, name='default_queue'):
self._name = name
self.q = []
self.delegate('append', 'pop', to='q')
@property
def all(self):
return self.q
que = Que('')
que.append(1)
que.append(2)
que.pop(0)
assert que.all == [2]It works well with classes inheriting its parent which uses @delegable.delegtor without any problem.
class Que2(Que):
def __init__(self, name='default_queue'):
super().__init__(name)
que1 = Que('')
que2 = Que2('')
que1.delegate('append', 'pop', to='q')
que2.delegate('append', 'pop', to='q')
que1.append(1)
que2.append(2)
assert que1.all == [1]
assert que2.all == [2]The decorator offers a property, delegates to define delegates all at once. Note it overwrites whole delegates but doesn't merge delegates.
@delegable.delegator
class Que:
def __init__(self, name='default_queue'):
self._name = name
self.q = []
self.delegate('append', 'pop', to='q')
self.delegates = {'s': 'join'}
assert que.join('ab') == 'a,b'
que.append(1)
# => AttributeError("'Que' object has no attribute 'append'")This project uses tox to test it against different versions of Python, with underlying pyenv.
You have to have pyenv installed to run tox in this project.
To test with all versions:
toxTo test with a certain version:
tox -e py37or
pyenv shell 3.7.7
pytest