Returns a flat list from a given nested structure.
nest is not a sequence, tuple, or dict, then returns a single-element
In the case of dict instances, the sequence consists of the values, sorted by
key to ensure deterministic behavior. This is true also for
instances: their sequence order is ignored, the sorting order of keys is
used instead. The same convention is followed in
correctly repacks dicts and
OrderedDicts after they have been flattened,
and also allows flattening an
OrderedDict and then repacking it back using
a corresponding plain dict, or vice-versa.
Dictionaries with non-sortable keys cannot be flattened.
Users must not modify any collections used in
nest while this function is
nest: an arbitrarily nested structure or a scalar object. Note, numpy arrays are considered scalars.
A Python list, the flattened version of the input.
TypeError: The nest is or contains a dict with non-sortable keys.