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# object.__new__(cls) is the only way in Python to allocate empty
# (non-initialized) instance of class.
# See e.g. http://infohost.nmt.edu/tcc/help/pubs/python/web/new-new-method.html
# TODO: Find reference in CPython docs
try:
# If we don't expose object.__new__ (small ports), there's
# nothing to test.
object.__new__
except AttributeError:
print("SKIP")
raise SystemExit
class Foo:
def __new__(cls):
# Should not be called in this test
print("in __new__")
raise RuntimeError
def __init__(self):
print("in __init__")
self.attr = "something"
o = object.__new__(Foo)
#print(o)
print("Result of __new__ has .attr:", hasattr(o, "attr"))
print("Result of __new__ is already a Foo:", isinstance(o, Foo))
o.__init__()
#print(dir(o))
print("After __init__ has .attr:", hasattr(o, "attr"))
print(".attr:", o.attr)
# should only be able to call __new__ on user types
try:
object.__new__(1)
except TypeError:
print("TypeError")
try:
object.__new__(int)
except TypeError:
print("TypeError")
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