shytools 1.0.1

Shy tools.

shytools

The shytools module provides tools to implement shy classes, that is, classes whose instances have real private attributes:

• shymethod - Shy methods decorator.

• shyproperty - Shy properties decorator.

• shytype - Shy abstract base class.

Usage

`from shytools import *`

`class MyShy(shytype):`

    `__slots__ = ()`

    `@shymethod`
    `def __init__(self):`
        `self.private = "spam"`

    `@shymethod`
    `def get(self):`
        `return self.private`

    `@shymethod`
    `def set(self, value):`
        `self.private = value`

    `@shyproperty`
    `def public(self):`
        `return self.private`

    `@public.setter`
    `def public(self, value):`
        `self.private = value`

`my_shy = MyShy()`

`print(my_shy.get()) # "spam"`
`print(my_shy.public) # "spam"`

`my_shy.set("eggs") # ok`

`print(my_shy.get()) # "eggs"`
`print(my_shy.public) # "eggs"`

`my_shy.public = "spam" # ok`

`print(my_shy.get()) # "spam"`
`print(my_shy.public) # "spam"`

`print(my_shy.private) # AttributeError`

Issues and limitations

• The shy subclasses must necessarily define an __slots__ attribute, and that attribute must necessarily be an empty tuple:

    `class MyShy(shytype):`
  
        `__slots__ = ()`
  

• Within shy properties and methods, self is not a real instance of the shy subclass:

    `class MyShy(shytype):`
  
        `__slots__ = ()`
  
        `@shymethod`
        `def __init__(self):`
            `print(isinstance(self, MyShy)) # False`
  
        `def regular_method(self):`
            `print(isinstance(self, MyShy)) # True`
  

• If the shy subclasses implement their own __new__ and __del__, they need to call __new__ and __del__ of the base class manually:

    `class MyShy(shytype):`
  
        `__slots__ = ()`
  
        `def __new__(cls, *pargs, **kwargs):`
            `my_shy = shytype.__new__(cls)`
            `<do something>`
            `return my_shy`
  
        `def __del__(self):`
            `<do something>`
            `shytype.__del__(self)`