U 3d @s>ddlmZddlmZddlmZGdddZddZdS) ) MethodType)wraps)update_wrapperc@s"eZdZdZddZdddZdS)_AvailableIfDescriptoravImplements a conditional property using the descriptor protocol. Using this class to create a decorator will raise an ``AttributeError`` if check(self) returns a falsey value. Note that if check raises an error this will also result in hasattr returning false. See https://docs.python.org/3/howto/descriptor.html for an explanation of descriptors. cCs ||_||_||_t||dS)N)fncheckattribute_namer)selfrrrr ?/tmp/pip-unpacked-wheel-zrfo1fqw/sklearn/utils/_available_if.py__init__sz_AvailableIfDescriptor.__init__Ncs`tdt|jdtj|dk rD|s6tj|}ntjfdd}|S)NzThis z has no attribute cs|dsj||S)Nr)rr)argskwargsZattr_errr r r out'sz+_AvailableIfDescriptor.__get__..out)AttributeErrorrepr__name__rrrrr)r objownerrr rr __get__s z_AvailableIfDescriptor.__get__)N)r __module__ __qualname____doc__r rr r r r rs rcs fddS)aAn attribute that is available only if check returns a truthy value. Parameters ---------- check : callable When passed the object with the decorated method, this should return a truthy value if the attribute is available, and either return False or raise an AttributeError if not available. Returns ------- callable Callable makes the decorated method available if `check` returns a truthy value, otherwise the decorated method is unavailable. Examples -------- >>> from sklearn.utils.metaestimators import available_if >>> class HelloIfEven: ... def __init__(self, x): ... self.x = x ... ... def _x_is_even(self): ... return self.x % 2 == 0 ... ... @available_if(_x_is_even) ... def say_hello(self): ... print("Hello") ... >>> obj = HelloIfEven(1) >>> hasattr(obj, "say_hello") False >>> obj.x = 2 >>> hasattr(obj, "say_hello") True >>> obj.say_hello() Hello cst||jdS)N)r)rr)rrr r Wzavailable_if..r rr rr available_if0s'rN)typesr functoolsrrrrr r r r s   *