dict_keys(['c', 'd', 'e', 'b', 'a']) # random order
Maybe I'm nit picky but I find the misuse of that word annoying. My experience of CPython is that dicts are unordered but deterministic. Not random.
dict_keys(['c', 'd', 'e', 'b', 'a']) # random order
Maybe I'm nit picky but I find the misuse of that word annoying. My experience of CPython is that dicts are unordered but deterministic. Not random.
d1 = dict()
d1['a'] = 1
d1['b'] = 1
print(d1.keys())
d2 = dict()
d2['a'] = 1
d2['b'] = 1
print(d2.keys())Seeded hashing was introduced to python 3.2.3: https://docs.python.org/3.3/using/cmdline.html#cmdoption-R
$ python3 --version
Python 3.5.2
$ python3 -c "print(hash('a'))"
6106879154137036349
$ python3 -c "print(hash('a'))"
9160572615033669802
$ python3 -c "print(set('abcdef'))"
{'d', 'f', 'e', 'b', 'c', 'a'}
$ python3 -c "print(set('abcdef'))"
{'e', 'f', 'd', 'a', 'b', 'c'}
d1 is d2 ⇒ list(d1) == list(d2)
d1 == d2 ⇏ list(d1) == list(d2)
x = {-1: (), -2: ()}
y = {-2: (), -1: ()}
list(x) != list(y)
It's worth noting that previously the order of two dictionaries with the same history was also the same (but may vary between program runs), but that was not guaranteed.
It's not actually clear if this is still regarded as an implementation detail, but I expect it will be effectively impossible to stop this becoming a key assumption of many libraries, so would expect any attempt to require OrderedDict (except for pre-3.6 compatibility) will fail.
Yet, the GP is just complaining about two different and widespread definitions of "random", so, whatever. It would be great to have a contexts dictionary we could use to resolve such things.