Coverage for src/gncpy/utilities.py: 0%

1import inspect 

2 

3 

4# helper classes to allow for classproperties similar to class methods 

5# see https://stackoverflow.com/questions/5189699/how-to-make-a-class-property 

6# for details 

7class ClassPropertyDescriptor(object): 

8 def __init__(self, fget, fset=None): 

9 self.fget = fget 

10 self.fset = fset 

11 

12 def __get__(self, obj, klass=None): 

13 if klass is None: 

14 klass = type(obj) 

15 return self.fget.__get__(obj, klass)() 

16 

17 def __set__(self, obj, value): 

18 if not self.fset: 

19 raise AttributeError("can't set attribute") 

20 if inspect.isclass(obj): 

21 type_ = obj 

22 obj = None 

23 else: 

24 type_ = type(obj) 

25 return self.fset.__get__(obj, type_)(value) 

26 

27 def setter(self, func): 

28 if not isinstance(func, (classmethod, staticmethod)): 

29 func = classmethod(func) 

30 self.fset = func 

31 return self 

32 

33 

34def classproperty(func): 

35 if not isinstance(func, (classmethod, staticmethod)): 

36 func = classmethod(func) 

37 

38 return ClassPropertyDescriptor(func) 

39 

40 

41class ClassPropertyMetaClass(type): 

42 def __setattr__(self, key, value): 

43 if key in self.__dict__: 

44 obj = self.__dict__.get(key) 

45 if obj and type(obj) is ClassPropertyDescriptor: 

46 return obj.__set__(self, value) 

47 

48 return super(ClassPropertyMetaClass, self).__setattr__(key, value)