This package includes helpers for special cases:
- SeparateClassMethod - allow to have classmethod and normal method both with the same name.
- AdvancedProperty - property with possibility to set class wide getter.
This descriptor can be set using standard decorator syntax. Create instance with arguments:
def imeth(instance):
return instance.value
def cmeth(owner):
return owner.value
class Target(object):
value = 1
def __init__(self):
self.value = 2
getval = advanced_descriptors.SeparateClassMethod(
imeth, cmeth
)Create instance wrapping as decorator:
class Target(object):
value = 1
def __init__(self):
self.value = 2
@advanced_descriptors.SeparateClassMethod
def getval(self):
return self.value
@getval.class_method
def getval(cls):
return cls.valueCases with method only and classmethod only is useless: method as-is and @classmethod should be used in corresponding cases.
Note
classmethod receives class as argument. IDE's don't know about custom descriptors and substitutes self by default.
This descriptor should be used in cases, when in addition to normal property API, class getter is required. If class-wide setter and deleter also required - you should use standard propery in metaclass.
Usage examples:
- In addition to normal property API:
class Target(object): _value = 777 def __init__(self): self._value = 42 @advanced_descriptors.AdvancedProperty def val(self): return self._value @val.setter def val(self, value): self._value = value @val.deleter def val(self): self._value = 0 @val.cgetter def val(cls): return cls._value
- Use class-wide getter for instance too:
class Target(object): _value = 1 val = advanced_descriptors.AdvancedProperty() @val.cgetter def val(cls): return cls._value
Note
class-wide getter receives class as argument. IDE's don't know about custom descriptors and substitutes self by default.
The main test mechanism for the package advanced-descriptors is using tox. Available environments can be collected via tox -l
For code checking several CI systems is used in parallel:
- Travis CI: is used for checking: PEP8, pylint, bandit, installation possibility and unit tests. Also it's publishes coverage on coveralls.
- coveralls: is used for coverage display.
Travis CI: is used for package delivery on PyPI.