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"""Proxy class for testing proxied objects."""
class Proxy:
"""Proxy to another object."""
# OBJECT PROXYING (PYTHON RECIPE)
# https://code.activestate.com/recipes/496741-object-proxying/
def __init__(self, obj):
object.__setattr__(self, "_obj", obj)
def __getattribute__(self, name):
return getattr(object.__getattribute__(self, "_obj"), name)
def __delattr__(self, name):
delattr(object.__getattribute__(self, "_obj"), name)
def __setattr__(self, name, value):
setattr(object.__getattribute__(self, "_obj"), name, value)
def __nonzero__(self):
return bool(object.__getattribute__(self, "_obj"))
def __str__(self):
return str(object.__getattribute__(self, "_obj"))
def __repr__(self):
return repr(object.__getattribute__(self, "_obj"))
_special_names = [
"__abs__",
"__add__",
"__and__",
"__call__",
"__cmp__",
"__coerce__",
"__contains__",
"__delitem__",
"__delslice__",
"__div__",
"__divmod__",
"__eq__",
"__float__",
"__floordiv__",
"__ge__",
"__getitem__",
"__getslice__",
"__gt__",
"__hash__",
"__hex__",
"__iadd__",
"__iand__",
"__idiv__",
"__idivmod__",
"__ifloordiv__",
"__ilshift__",
"__imod__",
"__imul__",
"__int__",
"__invert__",
"__ior__",
"__ipow__",
"__irshift__",
"__isub__",
"__iter__",
"__itruediv__",
"__ixor__",
"__le__",
"__len__",
"__long__",
"__lshift__",
"__lt__",
"__mod__",
"__mul__",
"__ne__",
"__neg__",
"__oct__",
"__or__",
"__pos__",
"__pow__",
"__radd__",
"__rand__",
"__rdiv__",
"__rdivmod__",
"__reduce__",
"__reduce_ex__",
"__repr__",
"__reversed__",
"__rfloorfiv__",
"__rlshift__",
"__rmod__",
"__rmul__",
"__ror__",
"__rpow__",
"__rrshift__",
"__rshift__",
"__rsub__",
"__rtruediv__",
"__rxor__",
"__setitem__",
"__setslice__",
"__sub__",
"__truediv__",
"__xor__",
"next",
]
@classmethod
def _create_class_proxy(cls, theclass):
"""Creates a proxy for the given class."""
def make_method(name):
def method(self, *args, **kw):
return getattr(object.__getattribute__(self, "_obj"), name)(*args, **kw)
return method
namespace = {}
for name in cls._special_names:
if hasattr(theclass, name):
namespace[name] = make_method(name)
return type(f"{cls.__name__}({theclass.__name__})", (cls,), namespace)
def __new__(cls, obj, *args, **kwargs):
"""Creates an proxy instance referencing `obj`.
(obj, *args, **kwargs) are passed to this class' __init__, so deriving
classes can define an __init__ method of their own.
note: _class_proxy_cache is unique per deriving class (each deriving
class must hold its own cache)
"""
try:
cache = cls.__dict__["_class_proxy_cache"]
except KeyError:
cls._class_proxy_cache = cache = {}
try:
theclass = cache[obj.__class__]
except KeyError:
cache[obj.__class__] = theclass = cls._create_class_proxy(obj.__class__)
ins = object.__new__(theclass)
theclass.__init__(ins, obj, *args, **kwargs)
return ins
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