py: Initial attempts to actually allow implementing __new__ in Python.

Caveat is that __new__ should recurse to base class __new__, and ultimately,
object.__new__ is what handles instance allocation.

1 files changed, 20 insertions, 0 deletions

diff --git a/tests/basics/object_new.py b/tests/basics/object_new.py
new file mode 100644
index 000000000..6131ed337
--- /dev/null
+++ b/tests/basics/object_new.py
@@ -0,0 +1,20 @@
+# 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
+
+class Foo:
+
+    def __init__(self):
+        print("in __init__")
+        self.attr = "something"
+
+
+o = object.__new__(Foo)
+#print(o)
+print(hasattr(o, "attr"))
+print(isinstance(o, Foo))
+o.__init__()
+#print(dir(o))
+print(hasattr(o, "attr"))
+print(o.attr)