The following worked fine under version 0.6.0, now existing keys get moved when new values are assigned.

Python 3.7.1 (default, Dec 14 2018, 13:28:58)
[Clang 4.0.1 (tags/RELEASE_401/final)] :: Anaconda, Inc. on darwin
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from pydicti import odicti
od = odicti(one=1, two=2, three=3)
print(od.keys())
odict_keys(['one', 'two', 'three'])
od['one'] = 1.0
print(od.keys())
odict_keys(['two', 'three', 'one'])