__init__ method for containers

[Neil Cerutti]

List and deque disagree on what __init__ does. Which one is
right?

Python 2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 32 bit (Intel)] on
win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from collections import deque
>>> x = deque([0, 1])
>>> x.__init__([2, 3])
>>> x
deque([0, 1, 2, 3])
>>> y = list([0, 1])
>>> y.__init__([2, 3])
>>> y
[2, 3]

test_deque.py even contains a test verifying its __init__
behavior, so perhaps deque has a good reason to differ from the
behavior of list.

Moreover, both methods use the same doc string, i.e.:

  __init__(...)
    x.__init__(...) initializes x; see x.__class__.__doc__ for signature

When implementing a list-like container extension type, is there
any reason to choose anything other than list-like behavior,
i.e., if you call __init__, you'll initialize the container?
deque's behavior doesn't make sense to me.

-- 
Neil Cerutti
One of the causes of the American Revolution was the English put tacks in
their tea. --History Exam Blooper