Right way to initialize an OrderedDict using its constructor such that it retains order of initial data?

What"s the correct way to initialize an ordered dictionary (OD) so that it retains the order of initial data?

from collections import OrderedDict

# Obviously wrong because regular dict loses order
d = OrderedDict({"b":2, "a":1}) 

# An OD is represented by a list of tuples, so would this work?
d = OrderedDict([("b",2), ("a", 1)])

# What about using a list comprehension, will "d" preserve the order of "l"
l = ["b", "a", "c", "aa"]
d = OrderedDict([(i,i) for i in l])

Question:

• Will an OrderedDict preserve the order of a list of tuples, or tuple of tuples or tuple of lists or list of lists etc. passed at the time of initialization (2nd & 3rd example above)?

• How does one go about verifying if OrderedDict actually maintains an order? Since a dict has an unpredictable order, what if my test vectors luckily have the same initial order as the unpredictable order of a dict? For example, if instead of d = OrderedDict({"b":2, "a":1}) I write d = OrderedDict({"a":1, "b":2}), I can wrongly conclude that the order is preserved. In this case, I found out that a dict is ordered alphabetically, but that may not be always true. What"s a reliable way to use a counterexample to verify whether a data structure preserves order or not, short of trying test vectors repeatedly until one breaks?

P.S. I"ll just leave this here for reference: "The OrderedDict constructor and update() method both accept keyword arguments, but their order is lost because Python’s function call semantics pass-in keyword arguments using a regular unordered dictionary"

P.P.S : Hopefully, in future, OrderedDict will preserve the order of kwargs also (example 1): http://bugs.python.org/issue16991