Advanced descriptors for special cases.
Project description
Advanced descriptors
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.
LogOnAccess - property with logging on successful get/set/delete or failure.
SeparateClassMethod
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.
AdvancedProperty
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
LogOnAccess
This special case of property is useful in cases, where a lot of properties should be logged by similar way without writing a lot of code.
Basic API is conform with property, but in addition it is possible to customize logger, log levels and log conditions.
Usage examples:
Simple usage. All by default. logger is re-used from instance if available with names logger or log else used internal advanced_descriptors.log_on_access logger:
import logging class Target(object): def init(self, val='ok') self.val = val self.logger = logging.get_logger(self.__class__.__name__) # Single for class, follow subclassing def __repr__(self): return "{cls}(val={self.val})".format(cls=self.__class__.__name__, self=self) @advanced_descriptors.LogOnAccess def ok(self): return self.val @ok.setter def ok(self, val): self.val = val @ok.deleter def ok(self): self.val = ""
Use with global logger for class:
class Target(object): def init(self, val='ok') self.val = val def __repr__(self): return "{cls}(val={self.val})".format(cls=self.__class__.__name__, self=self) @advanced_descriptors.LogOnAccess def ok(self): return self.val @ok.setter def ok(self, val): self.val = val @ok.deleter def ok(self): self.val = "" ok.logger = 'test_logger' ok.log_level = logging.INFO ok.exc_level = logging.ERROR ok.log_object_repr = True # As by default ok.log_success = True # As by default ok.log_failure = True # As by default ok.log_traceback = True # As by default ok.override_name = None # As by default: use original name
Testing
The main test mechanism for the package advanced-descriptors is using tox. Available environments can be collected via tox -l
CI systems
For CI/CD GitHub actions is used:
GitHub actions: is used for checking: PEP8, pylint, bandit, installation possibility and unit tests.
