Key-value consistency in python dictionaries

Yes it's always true. Guaranteed by Python iff there are no intervening modifications to the ditionary.

Relevant spec: http://docs.python.org/library/stdtypes.html#dict.items

This is better generally, both because it protects against the dict going out of sync and uses negligible extra memory:

dict((k,v) for k,v in d.iteritems())

Yes, this is a guaranteed behavior :-)

The keys and values are listed in the same order as returned by d.items: http://docs.python.org/library/stdtypes.html#dict.items

Note, in multi-threaded environments it is best to extract d.items() all at once rather than risk a mutation between successive calls to d.keys() and d.values().

If you're asking whether the keys and values are returned in the same order, the answer is Yes. The documentation says:

If items(), keys(), values(), iteritems(), iterkeys(), and itervalues() are called with no intervening modifications to the dictionary, the lists will directly correspond.

If you're asking whether dict( zip( d.keys(), d.values() ) ) == d will always evaluate to True under all circumstances, the answer is No. You can have multiple threads, with one changing d while the other one is executing d.keys(), d.values(), or dict(...). This will create intervening modifications, invalidating the conditions quoted above.